[Tutor] printing value returning from a Class
Hello friends,, I have a problem in displaying data which i have invoked from class. City is the name of the class which i havent displayed here. There is another script using that class. It has a function name setCities which takes a text file as argument. Text file contains name of the city, x and y location. there are 4 datas in 4 different lines. Code is as follows. import City def setCities(inFile): # puts city.txt content into City class objects # the field order of input file is: name x y x, y are integers. data are in newlines. f = open(inFile, 'r') body = f.readlines() f.close() cities = [] # list of cities for row in body: cityData = row.strip().split() cityName = cityData[0] cityX = cityData[1] cityY = cityData[2] newCity = City(cityName, cityX, cityY) # city class is invoked cities.append(newCity) return cities abc = setCities(C:\MS\sem5\Lab2_scripts\cities.txt) # setCities function will return the array with values read from the file. print abc I am getting output like [city.City instance at 0x023E82D8, city.City instance at 0x023E8300, city.City instance at 0x023E8350, city.City instance at 0x023E83C8] I want the data and not the instance... what should i do ?? -- Varsha Purohit, ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] 2.5 to 2.4 problem with Int
I've written a program which calculates areas of grid cells distributed over the globe. It works fine with Python 2.5, however, when I run it with 2.4(the Enthon edition) I get the following error: OverflowError: long int too large to convert to int It occurs on this line: for ix in range(nx): area[ix,iy]=gridarea I have no idea which int it's referring to? The values of ix/nx will not exceed 360, iy will not exceed 180. Any suggestions on what to change for the backward compatability? ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] editTextFile.py
Christopher Spears wrote:
I created a script that opens an existing text file,
allows the user to write over the original contents,
and then save the file. The original contents are
then saved in a separate file. Here is the script:
#!/usr/bin/python
'editTextFile.py -- write over contents of existing
text file'
import os, string
# get filename
while True:
fname = raw_input('Enter file name: ')
if not (os.path.exists(fname)):
print*** ERROR: '%s' doesn't exist % fname
else:
break
# get file content (text) lines
all = []
print \nEnter lines ('.' by itself to quit).\n
# loop until user terminates input
while True:
entry = raw_input(' ')
if entry == '.':
break
else:
all.append(entry)
# write lines to file with NEWLINE line terminator
print 1) Replace file's contents
print Any other key quits function without replacing
file's contents
choice = raw_input(Make a choice: )
if choice == '1':
fobj = open(fname, 'r')
fobj_lines = fobj.readlines()
fobj.close()
fobj = open(fname, 'w')
It would be safer to write the '_orig' file before opening the original
file for writing (which erases its contents)
fname_orig = fname + '_orig'
fobj_orig = open(fname_orig, 'w')
stripped_lines = []
for line in fobj_lines:
string.strip(line)
This doesn't change line. You need to assign the result back to line:
line = string.strip(line)
or, better,
line = line.strip()
Note that this will also strip leading and trailing whitespace from the
lines so the copy will not be a duplicate of the original.
A simpler way to copy a file is to read the entire contents using
fobj.read() and write them as a single string. Even easier is to use
shutil.copyfile() which does this for you.
Kent
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Re: [Tutor] 2.5 to 2.4 problem with Int
John wrote: I've written a program which calculates areas of grid cells distributed over the globe. It works fine with Python 2.5, however, when I run it with 2.4 (the Enthon edition) I get the following error: OverflowError: long int too large to convert to int It occurs on this line: for ix in range(nx): area[ix,iy]=gridarea I have no idea which int it's referring to? The values of ix/nx will not exceed 360, iy will not exceed 180. Any suggestions on what to change for the backward compatability? Are you sure nx is not large? The argument to range() must be an int. I would split the line in two so you know which part of it is generating the error, then insert a print statement to give you some more data. Kent ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] printing value returning from a Class
Hello! On 9/13/07, Varsha Purohit [EMAIL PROTECTED] wrote: Hello friends,, I have a problem in displaying data which i have invoked from class. City is the name of the class which i havent displayed here. There is another script using that class. It has a function name setCities which takes a text file as argument. Text file contains name of the city, x and y location. there are 4 datas in 4 different lines. Code is as follows. import City def setCities(inFile): # puts city.txt content into City class objects # the field order of input file is: name x y x, y are integers. data are in newlines. f = open(inFile, 'r') body = f.readlines() f.close() cities = [] # list of cities for row in body: cityData = row.strip().split() cityName = cityData[0] cityX = cityData[1] cityY = cityData[2] newCity = City(cityName, cityX, cityY) # city class is invoked cities.append(newCity) return cities abc = setCities(C:\MS\sem5\Lab2_scripts\cities.txt) # setCities function will return the array with values read from the file. print abc I am getting output like [city.City instance at 0x023E82D8, city.City instance at 0x023E8300, city.City instance at 0x023E8350, city.City instance at 0x023E83C8] I want the data and not the instance... what should i do ?? Well, that depends on the City class. When you print a list, it just calls repr() on each item in the list and prints that. Now, suppose there is a method printCity() in the City class for printing the city data. In that case you should probably just loop over the list of instances and call the method, like this: abc = setCities(city file) for city in abc: ... city.printCity() If there is no such method, maybe you can extract the data from the class and write your own printing function, or modify the class to add one. HTH, Kalle ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] is this a vista issue
Hi
when I run this code on a winxp box I get a nice list of url's
when I run this code on a win VISTA box I get this
print urlparse.urlparse(href)[1]TypeError: 'module' object is not callable
can a. someone tell me why b. how do i get rid of this condition before I
throw vista away :)
Many thanks in advance
S
[CODE]
from BeautifulSoup import BeautifulSoupdoc = ['htmlheadtitlePage
title/title/head', 'bodyp id=firstpara align=centerThis is
paragraph bone/b.', 'p id=secondpara align=blahThis is
paragraph btwo/b.', 'a href=http://www.google.co.uk;/a',
'a href=http://www.bbc.co.uk;/a', 'a
href=http://www.amazon.co.uk;/a', 'a
href=http://www.redhat.co.uk;/a', '/html']soup =
BeautifulSoup(''.join(doc))blist = soup.findAll('a')print blist
import urlparsefor a in blist:href = a['href']print
urlparse.urlparse(href)[1]
[/CODE]
_
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Re: [Tutor] is this a vista issue
sacha rook wrote:
Hi
when I run this code on a winxp box I get a nice list of url's
when I run this code on a win VISTA box I get this
print urlparse.urlparse(href)[1]
TypeError: 'module' object is not callable
Please show the whole traceback.
Kent
can a. someone tell me why b. how do i get rid of this condition
before I throw vista away :)
Many thanks in advance
S
[CODE]
from BeautifulSoup import BeautifulSoup
doc = ['htmlheadtitlePage title/title/head',
'bodyp id=firstpara align=centerThis is paragraph
bone/b.',
'p id=secondpara align=blahThis is paragraph btwo/b.',
'a href=http://www.google.co.uk;/a'
http://www.google.co.uk;/a',
'a href=http://www.bbc.co.uk;/a' http://www.bbc.co.uk;/a',
'a href=http://www.amazon.co.uk;/a'
http://www.amazon.co.uk;/a',
'a href=http://www.redhat.co.uk;/a'
http://www.redhat.co.uk;/a',
'/html']
soup = BeautifulSoup(''.join(doc))
blist = soup.findAll('a')
print blist
import urlparse
for a in blist:
href = a['href']
print urlparse.urlparse(href)[1]
[/CODE]
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Re: [Tutor] 2.5 to 2.4 problem with Int
The error occurs here: area[ix,iy]=gridarea The values of nx, ix, iy leading up to the error are: 360 0 0 360 1 0 360 2 0 360 3 0 360 4 0 360 ... ... 360 357 9 360 358 9 360 359 9 360 0 10 OverflowError: long int too large to convert to int I guess then the problem occurs when iy goes from 9 to 10, but why?? It wasn't a problem before and it's not a problem for ix??? Thanks! On 9/13/07, Kent Johnson [EMAIL PROTECTED] wrote: John wrote: I've written a program which calculates areas of grid cells distributed over the globe. It works fine with Python 2.5, however, when I run it with 2.4 (the Enthon edition) I get the following error: OverflowError: long int too large to convert to int It occurs on this line: for ix in range(nx): area[ix,iy]=gridarea I have no idea which int it's referring to? The values of ix/nx will not exceed 360, iy will not exceed 180. Any suggestions on what to change for the backward compatability? Are you sure nx is not large? The argument to range() must be an int. I would split the line in two so you know which part of it is generating the error, then insert a print statement to give you some more data. Kent -- Configuration `` Plone 2.5.3-final, CMF-1.6.4, Zope (Zope 2.9.7-final, python 2.4.4, linux2), Five 1.4.1, Python 2.4.4 (#1, Jul 3 2007, 22:58:17) [GCC 4.1.1 20070105 (Red Hat 4.1.1-51)], PIL 1.1.6 ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] 2.5 to 2.4 problem with Int
John wrote: The error occurs here: area[ix,iy]=gridarea What is area? Is it a dict or something else? What is gridarea? Please show more code and the complete traceback. Kent The values of nx, ix, iy leading up to the error are: 360 0 0 360 1 0 360 2 0 360 3 0 360 4 0 360 ... ... 360 357 9 360 358 9 360 359 9 360 0 10 OverflowError: long int too large to convert to int I guess then the problem occurs when iy goes from 9 to 10, but why?? It wasn't a problem before and it's not a problem for ix??? Thanks! ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] 2.5 to 2.4 problem with Int
In all it's glory: I'm just a bit embarrassed because I'm sure it's poor coding: def gridarea(H): returns an array of area corresponding to each nx,ny,nz %=== % %--- % input % - H : Header dict object with nx, ny, nz % % output % - Numpy array area corresponding to nx,ny,nz %--- % %--- % last changes: ww, 2007 %=== import math import numpy as N pih=math.pi/180. r_earth=6.371e6 cosfunc = lambda y : math.cos(y*pih)*r_earth nz=H['nz'] nx=H['nx'] ny=H['ny'] outlat0=H['outlat0'] dyout=H['dyout'] dxout=H['dxout'] area=N.zeros((nx,ny)) #creates numpy array for iy in range(ny): ylata=outlat0+(float(iy)+0.5)*dyout ylatp=ylata+0.5*dyout ylatm=ylata-0.5*dyout if (ylatm0 and ylatp0): hzone=dyout*r_earth*pih else: cosfact=cosfunc(ylata) cosfactp=cosfunc(ylatp) cosfactm=cosfunc(ylatm) if cosfactpcosfactm: hzone=math.sqrt(r_earth**2-cosfactp**2)-math.sqrt (r_earth**2-cosfactm**2) else: hzone=math.sqrt(r_earth**2-cosfactm**2)-math.sqrt (r_earth**2-cosfactp**2) gridarea=2.*math.pi*r_earth*hzone*dxout/360. for ix in range(nx): print nx, ix, iy area[ix,iy]=gridarea return area #returns numpy array of area Here's the traceback: ... 360 357 9 360 358 9 360 359 9 360 0 10 OverflowError: long int too large to convert to int Traceback: File string, line 1, in ? File c:\07\Programming\Python\mod_fp\getfp.py, line 11, in ? H,fail=readheader(pathname,1,0) File c:\07\Programming\Python\mod_fp\mod_fp.py, line 170, in readheader H['area'] = gridarea(H) File c:\07\Programming\Python\mod_fp\mod_fp.py, line 332, in gridarea area[ix,iy]=gridarea ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] Class Inheritance
Okay class A: def __init__(self,x,y): self.x = x self.y = y def save(self,fn): f = open(fn,w) f.write(str(self.x)+ '\n') # convert to a string and add newline f.write(str(self.y)+'\n') return f # for child objects to use def restore(self, fn): f = open(fn) self.x = int(f.readline()) # convert back to original type self.y = int(f.readline()) return f class B(A): def __init__(self,x,y,z): A.__init__(self,x,y) self.z = z def save(self,fn): f = A.save(self,fn) # call parent save f.write(str(self.z)+'\n') return f # in case further children exist def restore(self, fn): f = A.restore(self,fn) self.z = int(f.readline()) return f In the class B, I'm not understanding the A.__init(self,x,y) part. So its initializing the class A, and basically you can use the A class like normal? Part im confused about is the self.z, does that belong to the class A or class B? Else I think I'm understanding it correctly. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] 2.5 to 2.4 problem with Int
I have no clue; anyone else? Maybe you should try the numpy list. Kent John wrote: for the record: nx=360 ny=180 nz=1 On 9/13/07, *John* [EMAIL PROTECTED] mailto:[EMAIL PROTECTED] wrote: In all it's glory: I'm just a bit embarrassed because I'm sure it's poor coding: def gridarea(H): returns an array of area corresponding to each nx,ny,nz %=== % %--- % input % - H : Header dict object with nx, ny, nz % % output % - Numpy array area corresponding to nx,ny,nz %--- % %--- % last changes: ww, 2007 %=== import math import numpy as N pih=math.pi/180. r_earth=6.371e6 cosfunc = lambda y : math.cos(y*pih)*r_earth nz=H['nz'] nx=H['nx'] ny=H['ny'] outlat0=H['outlat0'] dyout=H['dyout'] dxout=H['dxout'] area=N.zeros((nx,ny)) #creates numpy array for iy in range(ny): ylata=outlat0+(float(iy)+0.5)*dyout ylatp=ylata+0.5*dyout ylatm=ylata-0.5*dyout if (ylatm0 and ylatp0): hzone=dyout*r_earth*pih else: cosfact=cosfunc(ylata) cosfactp=cosfunc(ylatp) cosfactm=cosfunc(ylatm) if cosfactpcosfactm: hzone=math.sqrt(r_earth**2-cosfactp**2)-math.sqrt(r_earth**2-cosfactm**2) else: hzone=math.sqrt(r_earth**2-cosfactm**2)-math.sqrt(r_earth**2-cosfactp**2) gridarea=2.*math.pi*r_earth*hzone*dxout/360. for ix in range(nx): print nx, ix, iy area[ix,iy]=gridarea return area #returns numpy array of area Here's the traceback: ... 360 357 9 360 358 9 360 359 9 360 0 10 OverflowError: long int too large to convert to int Traceback: File string, line 1, in ? File c:\07\Programming\Python\mod_fp\getfp.py, line 11, in ? H,fail=readheader(pathname,1,0) File c:\07\Programming\Python\mod_fp\mod_fp.py, line 170, in readheader H['area'] = gridarea(H) File c:\07\Programming\Python\mod_fp\mod_fp.py, line 332, in gridarea area[ix,iy]=gridarea -- Configuration `` Plone 2.5.3-final, CMF-1.6.4, Zope (Zope 2.9.7-final, python 2.4.4, linux2), Five 1.4.1, Python 2.4.4 (#1, Jul 3 2007, 22:58:17) [GCC 4.1.1 20070105 (Red Hat 4.1.1-51)], PIL 1.1.6 ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Class Inheritance
Lamonte Harris wrote: Okay class A: def __init__(self,x,y): self.x = x self.y = y def save(self,fn): f = open(fn,w) f.write(str(self.x)+ '\n') # convert to a string and add newline f.write(str(self.y)+'\n') return f # for child objects to use def restore(self, fn): f = open(fn) self.x = int(f.readline()) # convert back to original type self.y = int(f.readline()) return f class B(A): def __init__(self,x,y,z): A.__init__(self,x,y) self.z = z def save(self,fn): f = A.save(self,fn) # call parent save f.write(str(self.z)+'\n') return f # in case further children exist def restore(self, fn): f = A.restore(self,fn) self.z = int(f.readline()) return f In the class B, I'm not understanding the A.__init(self,x,y) part. So its initializing the class A, and basically you can use the A class like normal? Essentially, yes, but the way you've worded it is imprecise. Any instance of B is a subclass of A, essentially an A: Every boy is a male, but not all males are boys. When you override a method in a subclass you have essentially turned off all behavior in the parent method, including magic methods like the constructor. You have to call the parent constructor explicitly to get its benefits. A method of an instance can be called like this: instance.method() and python makes sure that a pointer to the instance is passed in as the first argument, generally self. But a method of a class can be called without instantiating the class, but you have to supply self on you own. The method you are using is valid, yet depricated. Using new style classes (which aren't actually that new) you'd write your code like this: class A(object): def __init__(self, a): self.aye = a class B(A): def __init__(self, a, b): self.bee = b super( B, self ).__init__( a ) Notice that you don't have to supply self. You can use any method of A in an instance of B that you haven't overridden in B without having to use super(). Part im confused about is the self.z, does that belong to the class A or class B? z is an attribute B only. Hope that helps, e. Else I think I'm understanding it correctly. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] evaluating AND
Given a variable x that can either be None or a tuple of two floats [i.e. (0.32, 4.2)], which syntax is considered most appropriate under Python coding standards? if x and x[0] 0: pass =OR= if x: if x[0] 0: pass In the first, I'm obviously making the assumption that if the first condition evaluates to false, then the second condition won't be evaluated. But, is this a good/valid assumption to make? Is there a more appropriate design pattern in Python? Thanks! Orest ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] evaluating AND
The first is how I would code it. Python guarantees that compound boolean statements are processed from left to right and also that the AND operator will short circuit the rest of the evaluation, since the rest of the line cannot change the falseness of the entire statement. Orest Kozyar wrote: Given a variable x that can either be None or a tuple of two floats [i.e. (0.32, 4.2)], which syntax is considered most appropriate under Python coding standards? if x and x[0] 0: pass =OR= if x: if x[0] 0: pass In the first, I'm obviously making the assumption that if the first condition evaluates to false, then the second condition won't be evaluated. But, is this a good/valid assumption to make? Is there a more appropriate design pattern in Python? Thanks! Orest ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] evaluating AND
On Thu, 13 Sep 2007, Orest Kozyar wrote: Given a variable x that can either be None or a tuple of two floats [i.e. (0.32, 4.2)], which syntax is considered most appropriate under Python coding standards? if x and x[0] 0: pass =OR= if x: if x[0] 0: pass I would like either one if instead of if x you used if x is not None; that seems a lot easier to me to read. It's a bit jarring to see the same variable used in one expression as both a boolean and a list/tuple. Besides, suppose somehow x got set to zero. It would pass without error, something you wouldn't want to have happen. Even if you've set things up so that it couldn't happen, it's not obvious from looking at this code that it couldn't happen. If you really want to test for x being non-None, test for x being non-None. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] Killing an instance
I have two instances called and running. They interact with each other and I would like one of the instances to cease to exist in the second round based on a given condition. How do you kill an instance? The code is below. I have Red and Yellow as my instances and I want them to die when life = 0 and not show up in the preceding rounds of the game. Thank you. Ara CODE HERE: ## #Red and Yellow yeast model # #Both yeast start out cooperating. #If the yeast detect that there is no ade or lys present they will defect #but die. ## import time chemicals = [] #0 cooperates #1 defects class RedYeast: #Needs adenine to grow, releases lysine def __init__(self,name,group): self.name = name self.group = group self.life = 1 self.hate_tolerance = 0 self.choice = 0 #METHODS def lys_re(self,stuffa): #release of lys in the environment if self.choice == 0: print self.name, -- Releasing lys chemicals.append(stuffa) elif self.choice == 1: print self.name, -- Withholds lys def ade_need(self,stuffb): if stuffb != chemicals: print self.name,is taking ade self.life = self.life+1 chemicals.remove(stuffb) print chemicals print Life, self.life else: print No ade presents self.life = self.life-1 self.choice = 1 class YellowYeast: #Needs lysine to grow, releases adenine def __init__(self,name,group): self.name = name self.group = group self.life = 1 self.hate_tolerance = 0 self.choice = 0 #METHODS def ade_re(self,stuffa): #release of lys in the environment if self.choice == 0: print self.name, -- Releasing ade chemicals.append(stuffa) elif self.choice == 1: print self.name, -- Withholds ade def lys_need(self,stuffb): if stuffb != chemicals: print self.name, is taking ade self.life = self.life+1 chemicals.remove(stuffb) print chemicals print Life,self.life print else: print No ade presents self.life = self.life-1 self.choice = 1 def death(self): ## #Start of program ## rounds = raw_input(How many rounds to you wish to play through?) print Starting environment, chemicals rounds =int(rounds) count = 0 #Creates the instances for RedYeast and YellowYeast one = RedYeast(Red,alpha) two = YellowYeast(Yellow,alpha) #Game logic while count rounds: print ## print one.lys_re(lys) two.ade_re(ade) print print Chemicals in the environment,chemicals print time.sleep(1) one.ade_need(ade) two.lys_need(lys) print ## print count = count+1 print Ending environment, chemicals -- Quis hic locus, quae regio, quae mundi plaga. Ubi sum. Sub ortu solis an sub cardine glacialis ursae. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] evaluating AND
Orest Kozyar wrote: Given a variable x that can either be None or a tuple of two floats [i.e. (0.32, 4.2)], which syntax is considered most appropriate under Python coding standards? if x and x[0] 0: pass =OR= if x: if x[0] 0: pass The first is fine. In the first, I'm obviously making the assumption that if the first condition evaluates to false, then the second condition won't be evaluated. But, is this a good/valid assumption to make? Yes, this is guaranteed by the language. http://docs.python.org/ref/Booleans.html Kent ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] evaluating AND
On 13/09/2007, Terry Carroll [EMAIL PROTECTED] wrote: On Thu, 13 Sep 2007, Orest Kozyar wrote: Given a variable x that can either be None or a tuple of two floats [i.e . (0.32, 4.2)], which syntax is considered most appropriate under Python coding standards? if x and x[0] 0: pass =OR= if x: if x[0] 0: pass I would like either one if instead of if x you used if x is not None; that seems a lot easier to me to read. It's a bit jarring to see the same variable used in one expression as both a boolean and a list/tuple. Besides, suppose somehow x got set to zero. It would pass without error, something you wouldn't want to have happen. Even if you've set things up so that it couldn't happen, it's not obvious from looking at this code that it couldn't happen. If you really want to test for x being non-None, test for x being non-None. The problem is what if it's an empty list or tuple? It would pass but have not value whereas if x would work fine. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] evaluating AND
On Thu, 13 Sep 2007, Adam Bark wrote: The problem is what if it's an empty list or tuple? It would pass but have not value whereas if x would work fine. Exactly. The poster stated that x is supposed to be either None or a tuple of two floats. Just to put a bit of meat on the example, let's create a function whose job is to return x[1]/x[0], but only if x[0] 0. Otherwise, it just falls off, i.e., returning None. Here are two versions, one using if x is None; the other using just if x def test01(x): ... if x is not None: ... if x[0]0: ...return x[1]/x[0] ... def test02(x): ... if x: ... if x[0]0: ...return x[1]/x[0] When x is None, both work: x = None print test01(x) None print test02(x) None When x is, in fact, a tuple of two floats, both work: x = (2.0, 5.0) print test01(x) 2.5 print test02(x) 2.5 Now... if x is an empty tuple: x = tuple() print test01(x) Traceback (most recent call last): File stdin, line 1, in module File stdin, line 3, in test01 IndexError: tuple index out of range print test02(x) None The first one, which checks if x is None fails. This is a good thing. The second one, which just checks if x and is satisfied with any false value, including an empty tuple, does not raise the error condition, even though the data is bad. This is a bad thing. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Suggested books for Agile Programming Testing
Shannon -jj Behrens [EMAIL PROTECTED] wrote Also, can anyone comment on the limits or caveats of agile development? I posted a longish response on this but it seems not to have made to gmane! Here it is again: === Stephen McInerney [EMAIL PROTECTED] wrote Can anyone recommend me the best single must-read book for Agile Programming? One of the most widely cited is Robert Martin's Agile Software Development. Personally I didn't like it much for agile but it is quite good on OOD. The original XP book by Kent Beck is good too, along with its sequel. Also Agile Testing. Sorry I can't comment on any specific testing books. (If they compare Agile in general to the other methodologies, that would be great) The best comparison book I can recommend is Balancing Agility Discipline by Barry Boehm. Also, can anyone comment on the limits or caveats of agile development? I'm sure lots of people can but Agile is such a nebulous concept that its difficult to get anything objective or useful. My own personal experieces follow for what they are wrth: Agile works well if: 1) You have very close contact with end users/requirement owners 2) Small, co-located teams - small = 20 or less people 3) The requirements are not clearly understood (even by the users). 4) You have an experienced, talented team You need *all* of those to make it work significantly better than traditional methods. If even one if missing you will be no better off. You might not be any worse off, but you will be no better. If you have only one of those items then traditional methods (NOT waterfall!) will be better. Dangers of agile: 1) Not good for building scaleable, resilient, long term flexible structures 2) Very expensive due to the large proportion of time spent in rework (aka refactoring) 3) Tendency to drift over budget as new featiures get thought up and added to the original scope. 4) Not good for long term maintenance, the documentation often being inadeqate for anyone outside of the original project team Note, All of these things can be addressed but it takes specific, directed action to do so. Some general comments: 1) Its easy for management to embrace agile by adopting some bits that they like. Requirements become User Stories, Progress meetings become Stand-Ups, Phased releases become iterations. in fact its just a renaming exercise not real Agile. Re-naming doesn't work, agile does (with the caveats above) 2) Agile is very open to hype. Exaggerated claims and comparisons with the waterfall method are common, even though the waterfall method has not been widely used for years and methods like RUP are more appropriate comparisons. If you compare a motorcycle to a penny farthing cycle you will get an exaggerated idea of progress 3) Agile badly done is just as bad as traditional badly done. 4) finally, do you need to hire an architect to build a garden shed? Agile is in some ways addressing an artificial problem. Software engineeering was invented in the late 70's to deal with very large projects. Most methodologies still tackle that problem. Many software houses now work on much smaller problems that only need small teams and can be completed in a few weeks. If you apply traditional methodologies to those problems they will be overkill. So Agile comes along. But on these very small projects, usually all that's needed is some common sense and experience - like building a garden shed! My personal career jhas been based on large projects. On most large projects there is a tools team who churn out little programs used by the main development/test teams. The tools team does not typically apply the main project methodology for each tool written, they just get on with it. The tools team will typically be 4-10 people. A tool will typically take 1-20 days to write. In other words the small end of Agile, but they don't use Agile, they don't use anything but common sense and their experiece... That's way more than I intended writing! I'm sure others will have different views. HTH, -- Alan Gauld Author of the Learn to Program web site http://www.freenetpages.co.uk/hp/alan.gauld ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] 2.5 to 2.4 problem with Int
John [EMAIL PROTECTED] wrote In all it's glory: I'm just a bit embarrassed because I'm sure it's poor coding: Thats what we're here for... The first thing to note is that gridarea is here a function object. So are you assigning the function object to area[x,y]. Is that what you intend? def gridarea(H): returns an array of area corresponding to each nx,ny,nz % input % - H : Header dict object with nx, ny, nz % output % - Numpy array area corresponding to nx,ny,nz import math import numpy as N It's traditional to put the imports outside the function, especially if they will always be called. pih=math.pi/180. r_earth=6.371e6 cosfunc = lambda y : math.cos(y*pih)*r_earth You could use the more conventional def cosfunc(y): return math.cos(y*pih)*r_earth lambda is fine by me but some folks find them harder to read. nz=H['nz'] nx=H['nx'] ny=H['ny'] outlat0=H['outlat0'] dyout=H['dyout'] dxout=H['dxout'] area=N.zeros((nx,ny)) #creates numpy array for iy in range(ny): ylata=outlat0+(float(iy)+0.5)*dyout ylatp=ylata+0.5*dyout ylatm=ylata-0.5*dyout if (ylatm0 and ylatp0): hzone=dyout*r_earth*pih else: cosfact=cosfunc(ylata) cosfactp=cosfunc(ylatp) cosfactm=cosfunc(ylatm) if cosfactp cosfactm: hzone=math.sqrt(r_earth**2-cosfactp**2)-math.sqrt (r_earth**2-cosfactm**2) else: hzone=math.sqrt(r_earth**2-cosfactm**2)-math.sqrt (r_earth**2-cosfactp**2) More whitespace will help readability and avoid errors! please... gridarea=2.*math.pi*r_earth*hzone*dxout/360. This is a bit iffy since you are creating a variable gridarea inside a function gridarea. That effectively removes the possibility of using recursion, although otherwise I don't *think* it should cause a problem in itself. for ix in range(nx): print nx, ix, iy area[ix,iy]=gridarea And here looks like we have the dodgy line because you are assigning the internal variable not the function after all. So gridarea is actually the result of that big calculation. That is a float value and potentially big, I don't know. Did you try printing the value of gridarea in your debug trace? But that shouldn't cause the error since you aren't trying to convert it to an int. Very odd. iy is set in the loop up to ny. But how does it compare to the original ny parameter you passed to N.zeros at the top? Is this a numpy index error we are actually seeing? I don't know how numpy's zeros function works... I'm clutching at straws here... return area #returns numpy array of area Here's the traceback: ... 360 357 9 360 358 9 360 359 9 360 0 10 So this is where we loop all the way back to the outer loop and then start the second loop again.. Can you add gridarea and ny to the debug data? OverflowError: long int too large to convert to int Traceback: File string, line 1, in ? File c:\07\Programming\Python\mod_fp\getfp.py, line 11, in ? H,fail=readheader(pathname,1,0) File c:\07\Programming\Python\mod_fp\mod_fp.py, line 170, in readheader H['area'] = gridarea(H) File c:\07\Programming\Python\mod_fp\mod_fp.py, line 332, in gridarea area[ix,iy]=gridarea Personally I'd change gridarea() to take the individiual parameters rather than the dictionary. There is a shortcut way of doing that using **kwords which means you canb pass the dictionary but the unpacking will be done for you by Python... But most of my comments are stylistic, I have no real idea whats going wrong here. Sorry. -- Alan Gauld Author of the Learn to Program web site http://www.freenetpages.co.uk/hp/alan.gauld ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Killing an instance
Ara Kooser [EMAIL PROTECTED] wrote I have two instances called and running. They interact with each other and I would like one of the instances to cease to exist in the second round based on a given condition. How do you kill an instance? Either set the variable to something else or explicitly with del() class C: pass c = C() # create a C instance c = 42 # the C instance gets garbage collected or c -= C() # another instance del(c) # delete it. HTH, -- Alan Gauld Author of the Learn to Program web site http://www.freenetpages.co.uk/hp/alan.gauld ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Killing an instance
Ara Kooser [EMAIL PROTECTED] wrote The code is below. I have Red and Yellow as my instances and I want them to die when life = 0 and not show up in the preceding rounds of the game. I'm not sure I understand this last bit. Won't they already have shown up in the preceding bits of the game. Setting to zero won't affect the preceding rounds unless you only display all of the rounds at the end and keep the records in memory. In which case you could go back and retrospectively change the earlier displays. It sounds a bit odd tho' can you elaborate? Alan G. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] deleting one line in multiple files
Greetings, I'm running Python 2.4.3 on a GNU/Linux box. This question is about using 'fileinput.' I have a directory of files, and I've created a file list of the files I want to work on: $ ls file.list Each file in file.list needs to have a line removed, leaving the rest of the file intact. I found this snippet on the Net, and it works fine for one file: # the lines with 'script type' are deleted. import fileinput for line in fileinput.input(file0001.html, inplace=1): line = line.strip() if not 'script type'in line: print line The docs say: This iterates over the lines of all files listed in sys.argv[1:]... I'm not sure how to implement the argv stuff. However, the documentation also states: To specify an alternative list of filenames, pass it as the first argument to input(). A single file name is also allowed. So, when I replace file0001.html with file.list (the alternative list of filenames, nothing happens. # the lines with 'script type' are deleted. import fileinput for line in fileinput.input(file.list, inplace=1): line = line.strip() if not 'script type'in line: print line file.list has one filename on each line, ending with a newline. file0001.html file0002.html ::: ::: file0175.html Have I interpreted the documentation wrong? The goal is to delete the line that has 'script type' in it. I can supply more information if needed. TIA. -- bhaaluu at gmail dot com ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] deleting one line in multiple files
I think the problem is that the original script you borrowed looks at the file passed to input, and iterates over the lines in that file, removing them if they match your pattern. What you actually want to be doing is iterating over the lines of your list file, and for each line (which represents a file), you want to open *that* file, do the check for your pattern, and delete appropriately. Hope I am not completely off:-) If I am right so far, you want to do something like: import fileinput for file in fileinput.input(filelist.list, inplace=1): curfile = file.open() for line in curfile: line = line.strip() if not 'script type'in line: print line BUT, fileinput was made (if I understand the documentation) to avoid having to do this. This is where the sys.argv[1:] values come in. The example on this page (look under Processing Each Line of One or More Files: The fileinput Module) helped clarify it to me: http://www.oreilly.com/catalog/lpython/chapter/ch09.html. If you do: % python myscript.py script type `ls` This should pass in all the items in the folder you run this in (be sure it only contains the files you want to edit!), looking for script type. Continuing with the O'Reilly example: import fileinput, sys, string # take the first argument out of sys.argv and assign it to searchterm searchterm, sys.argv[1:] = sys.argv[1], sys.argv[2:] for line in fileinput.input(): num_matches = string.count(line, searchterm) if num_matches: # a nonzero count means there was a match print found '%s' %d times in %s on line %d. % (searchterm, num_matches, fileinput.filename(), fileinput.filelineno()) To test this, I put the above code block in mygrep.py, then made a file test.txt in the same folder, with some trash lines, and 1 line with the string you said you want to match on. Then I did: [EMAIL PROTECTED]:~$ python mygrep.py script type test.txt found 'script type' 1 times in test.txt on line 3. So you could use the above block, and edit the print line to also edit the file as you want, maybe leaving the print to confirm it did what you expect. Hope this helps! -Sam _ I have a directory of files, and I've created a file list of the files I want to work on: $ ls file.list Each file in file.list needs to have a line removed, leaving the rest of the file intact. I found this snippet on the Net, and it works fine for one file: # the lines with 'script type' are deleted. import fileinput for line in fileinput.input(file0001.html, inplace=1): line = line.strip() if not 'script type'in line: print line The docs say: This iterates over the lines of all files listed in sys.argv[1:]... I'm not sure how to implement the argv stuff. However, the documentation also states: To specify an alternative list of filenames, pass it as the first argument to input(). A single file name is also allowed. So, when I replace file0001.html with file.list (the alternative list of filenames, nothing happens. # the lines with 'script type' are deleted. import fileinput for line in fileinput.input(file.list, inplace=1): line = line.strip() if not 'script type'in line: print line file.list has one filename on each line, ending with a newline. file0001.html file0002.html ::: ::: file0175.html Have I interpreted the documentation wrong? The goal is to delete the line that has 'script type' in it. I can supply more information if needed. TIA. -- bhaaluu at gmail dot com ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] How can I extend my vocabulary that fits well with python.
See theres a lot of words that I know and some that I don't know, how can I extend and improve my python vocabulary so I can interpret information in a faster manor. Makes things easier to understand if you actually understand the things the people are saying in tutorials,etc.. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] evaluating AND
On 14/09/2007, Terry Carroll [EMAIL PROTECTED] wrote: The second one, which just checks if x and is satisfied with any false value, including an empty tuple, does not raise the error condition, even though the data is bad. This is a bad thing. For me, if x would be enough. If you think it's a bad thing when x is of the wrong data, then you really should check that it contains *correct* data as well. Using the the two function of yours, setting x to an integer: x = 2 print test01(x) Traceback (most recent call last): File stdin, line 1, in ? File /usr/tmp/python-3716vZq, line 3, in test01 TypeError: unsubscriptable object print test02(x) Traceback (most recent call last): File stdin, line 1, in ? File /usr/tmp/python-3716vZq, line 8, in test02 TypeError: unsubscriptable object Rewriting your test01-function into this: def test01(x): if (type(x) == type((0,)) and (x is not None) and (length(x) == 2)): if x[0]0: return x[1]/x[0] and testing again: x = 2 print test01(x) None My point is that if you think it's bad for a function to receive incorrect data you should do exhaustive checks for the input to make sure it is of correct type, size and whatever the requirements might be, not just check if it's a tuple or not. -- - Rikard - http://bos.hack.org/cv/ ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] is this a vista issue
On 13/09/2007, sacha rook [EMAIL PROTECTED] wrote:
[CODE]
from BeautifulSoup import BeautifulSoup
doc = ['htmlheadtitlePage title/title/head',
'bodyp id=firstpara align=centerThis is paragraph
bone/b.',
'p id=secondpara align=blahThis is paragraph btwo/b.',
'a href=http://www.google.co.uk;/a',
'a href=http://www.bbc.co.uk;/a',
'a href=http://www.amazon.co.uk;/a',
'a href=http://www.redhat.co.uk;/a',
'/html']
soup = BeautifulSoup(''.join(doc))
blist = soup.findAll('a')
print blist
import urlparse
for a in blist:
href = a['href']
print urlparse.urlparse(href)[1]
[/CODE]
Works fine for me:
## working on region in file python-tmp-371673F...
[a href=http://www.google.co.uk;/a, a
href=http://www.bbc.co.uk;/a, a
href=http://www.amazon.co.uk;/a, a
href=http://www.redhat.co.uk;/a]
www.google.co.uk
www.bbc.co.uk
www.amazon.co.uk
www.redhat.co.uk
But as Kent wrote; show the whole traceback, not just the last line.
--
- Rikard - http://bos.hack.org/cv/
___
Tutor maillist - Tutor@python.org
http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] evaluating AND
On 14/09/2007, Rikard Bosnjakovic [EMAIL PROTECTED] wrote: On 14/09/2007, Terry Carroll [EMAIL PROTECTED] wrote: The second one, which just checks if x and is satisfied with any false value, including an empty tuple, does not raise the error condition, even though the data is bad. This is a bad thing. My point is that if you think it's bad for a function to receive incorrect data you should do exhaustive checks for the input to make sure it is of correct type, size and whatever the requirements might be, not just check if it's a tuple or not. I think Terry's viewpoint is that a function should raise an exception if it receives bad data. You don't need to do exhaustive isinstance()/type() tests; just use the data as if it is what you're expecting and let errors happen if the data is wrong. What's important is that the function should not return valid output when given invalid input. That's what could happen with Terry's hypothetical test02() if you give it an empty list. OTOH, if you give either function an integer, both will raise exceptions, which is fine. You could change the function like this, though, to ensure the list length is correct: def test01(x): ... if x is not None: ... assert len(x)==2 ... if x[0]0: ...return x[1]/x[0] ... -- John. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] deleting one line in multiple files
Thought I would do some more testing and get you a more finalized form this time. So I took the mygrep.py script, and put it in a folder with 3 test files with content like this: I am some lines of text yep I love text 435345 345345345 script type=text/javascript / Then I ran: [EMAIL PROTECTED]:~/test$ python mygrep.py script type `ls` found 'script type' 1 times in test1.txt on line 6. found 'script type' 1 times in test2.txt on line 6. found 'script type' 1 times in test3.txt on line 6. This will work in your case quite well I think. Now for doing the actual delete... I could not find a way to succinctly delete a single line from the files in Python, but I am almost there. Sorry, it was late:-) import fileinput, sys, string # take the first argument out of sys.argv and assign it to searchterm searchterm, sys.argv[1:] = sys.argv[1], sys.argv[2:] for line in fileinput.input(): num_matches = string.count(line, searchterm) if num_matches: # a nonzero count means there was a match print found '%s' %d times in %s on line %d. % (searchterm, num_matches, fileinput.filename(), fileinput.filelineno()) thisfile = open(fileinput.filename(), r) linelist = thisfile.readlines() del linelist[(fileinput.filelineno() -1)] print linelist thisfile.close() print Deleted %s line(s) containing pattern in %s % (num_matches, fileinput.filename()) So this will do the search on the file you specify at runtime, look for the pattern you specify, and print out a list of the lines with the matching line removed. Now I need to write these lines back to the original file. Don't have that part yet...:-( -Sam ___ - Original Message From: wormwood_3 [EMAIL PROTECTED] To: Python Tutorlist tutor@python.org Sent: Thursday, September 13, 2007 11:33:48 PM Subject: [Tutor] deleting one line in multiple files I think the problem is that the original script you borrowed looks at the file passed to input, and iterates over the lines in that file, removing them if they match your pattern. What you actually want to be doing is iterating over the lines of your list file, and for each line (which represents a file), you want to open *that* file, do the check for your pattern, and delete appropriately. Hope I am not completely off:-) If I am right so far, you want to do something like: import fileinput for file in fileinput.input(filelist.list, inplace=1): curfile = file.open() for line in curfile: line = line.strip() if not 'script type'in line: print line BUT, fileinput was made (if I understand the documentation) to avoid having to do this. This is where the sys.argv[1:] values come in. The example on this page (look under Processing Each Line of One or More Files: The fileinput Module) helped clarify it to me: http://www.oreilly.com/catalog/lpython/chapter/ch09.html. If you do: % python myscript.py script type `ls` This should pass in all the items in the folder you run this in (be sure it only contains the files you want to edit!), looking for script type. Continuing with the O'Reilly example: import fileinput, sys, string # take the first argument out of sys.argv and assign it to searchterm searchterm, sys.argv[1:] = sys.argv[1], sys.argv[2:] for line in fileinput.input(): num_matches = string.count(line, searchterm) if num_matches: # a nonzero count means there was a match print found '%s' %d times in %s on line %d. % (searchterm, num_matches, fileinput.filename(), fileinput.filelineno()) To test this, I put the above code block in mygrep.py, then made a file test.txt in the same folder, with some trash lines, and 1 line with the string you said you want to match on. Then I did: [EMAIL PROTECTED]:~$ python mygrep.py script type test.txt found 'script type' 1 times in test.txt on line 3. So you could use the above block, and edit the print line to also edit the file as you want, maybe leaving the print to confirm it did what you expect. Hope this helps! -Sam _ I have a directory of files, and I've created a file list of the files I want to work on: $ ls file.list Each file in file.list needs to have a line removed, leaving the rest of the file intact. I found this snippet on the Net, and it works fine for one file: # the lines with 'script type' are deleted. import fileinput for line in fileinput.input(file0001.html, inplace=1): line = line.strip() if not 'script type'in line: print line The docs say: This iterates over the lines of all files listed in sys.argv[1:]... I'm not sure how to implement the argv stuff. However, the documentation also states: To specify an alternative list of filenames, pass it as the first argument to input(). A single file name is also allowed. So, when I replace file0001.html with file.list (the
