[Tutor] Confused about import Numeric vs import numpy for Arrays
Hi Everyone, I would like to create a two-dimensional array but am confused as to how to go about it. I've read about Numeric Python and Numpy. Are they one and the same? Also, how do I install them? I am working on a Windows machine. I've been getting the following error messages: import Numeric Traceback (most recent call last): File pyshell#3, line 1, in module import Numeric ImportError: No module named Numeric from Numeric import * Traceback (most recent call last): File pyshell#4, line 1, in module from Numeric import * ImportError: No module named Numeric I then downloaded and installed release 1.1.1 of the Numpy package from this site: http://sourceforge.net/project/showfiles.php?group_id=1369package_id=175103 After restarting the shell, I still get the same errors above (though I do have this directory now: C:\Python25\Lib\site-packages\numpy). Anyone know how to correctly install and use this package? Thanks in advance. Samir ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Confused about import Numeric vs import numpy for Arrays
No, they are not the same. Numeric is older; NumArray is another older package. You should use Numpy if you can. http://numpy.scipy.org/#older_array snip Now you should be able to import numpy. Kent Thanks, Kent. I ended up using: from numpy import * I wasn't sure what the difference was between this and import numpy Thanks! Samir ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Confused about import Numeric vs import numpy for Arrays
In general from module import * is a very bad idea. import module imports a module into its own namespace (e.g., to access its functionality you would have to do module.foo() and module.bar() The form that you chose to use imports all of a module's contents into the current namespace. This means you can call foo() and bar() directly, but it also means that if you have coded a foo() and a bar() you will not have access to the functions in the module you just imported. Timothy, Thanks for the clarification. I had always wondered what the difference was. Samir ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Confused about import Numeric vs import numpy forArrays
A useful tip is that if you have a long module name you can also use import module as shortname eg import numpy as n and then access numpy.foo() as n.foo() Sacves a lot of typing for a slight loss of clarity in maintenance - you have to remember which module the short names refer to! I tend to use full names in real code and use the abbreviated form when using the prompt. Alan - Great suggestion! As I'm reading through the numpy documentation, there are a lot of great functions that I'd like to learn to use so your advice definitely helps. I was getting tired of constantly having to type numpy.array or numpy.ones all the time. Thanks again. Samir ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Confused about import Numeric vs import numpy for Arrays
Another reason not to use from xx import * is that it can make it very difficult to discover where a name is defined. If you have several from xx import * lines and then later you use a function foo() there is no easy way to tell which module foo came from. An alternative is to list just the names you want to import: from xx import foo Kent Kent - Another great point. Thanks for contributing to the list. Samir ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
[Tutor] Reading List from File
Hi Everyone,
I am trying to read a comma-delimitted list (aaa,bbb,ccc) from a text
file and assign those values to a list, x, such that:
x = [aaa, bbb, ccc]
The code that I have come up with looks like this:
x = []
f = open(r'c:\test.txt', 'r')
x.extend(f.readlines())
x
['aaa,bbb,ccc']
If you look closely, there is an extra pair of single quotes (') that
encapsulates the string. Therefore, len(x) returns 1, instead of 3. Is
there a function to separate this list out? I hope my question makes
sense.
Thanks in advance.
Samir
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Re: [Tutor] Reading List from File
Hi Everyone,
Thanks for the variety of responses in such a short amount of time.
This distribution list is incredible.
Sorry for the delayed reply as I wanted to test what everyone
suggested, so here goes:
---
@Amin: I tried your suggestion, but perhaps I don't understand your
syntax. Here is what I tried and the resulting error message:
f = open(r'C:\test.txt', 'r')
foo = f.readline.split(',')
Traceback (most recent call last):
File pyshell#16, line 1, in module
foo = f.readline.split(',')
AttributeError: 'builtin_function_or_method' object has no attribute 'split'
Do you know what I did wrong?
---
@Emad, Brett: Thank you for your solutions. They do exactly what I
was looking for.
---
@Chad: Thanks for your suggestion. I think I like it best for its simplicity.
---
@Emile, Monika, kinuthi: The CSV standard library looks interesting
but I am having mixed results in implementing it. For example, it
works when I try this:
reader = csv.reader(open(r'c:\test.txt', 'rb'))
for row in reader:
print row
['aaa', 'bbb', 'ccc']
but it fails when I try:
import csv
myfile = open(r'c:\test.txt', 'r')
data = csv.Reader(myfile, delimeter = ',')
Traceback (most recent call last):
File pyshell#26, line 1, in module
data = csv.Reader(myfile, delimeter = ',')
AttributeError: 'module' object has no attribute 'Reader'
The error looks similar to what I received when I tried Amin's
approach. Am I missing something?
---
It's interesting to note that for the solutions to work correctly, I
had to remove the quotation marks from the input file.
Thanks again to EVERYONE who took the time to respond. I appreciate your help.
Samir
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Re: [Tutor] Reading List from File
Monika,
Thanks for your help. I got it to work using the following (also had
to spell delimiter):
import csv
myfile = open(r'c:\test.txt', 'r')
data = csv.reader(myfile, delimiter=',')
print data
_csv.reader object at 0x00D41870
for item in data:
print item
['aaa', 'bbb', 'ccc']
I think it was referred to in another post, but I have found this page
to be helpful:
http://docs.python.org/lib/csv-examples.html
Thanks.
Samir
On Thu, Jul 31, 2008 at 2:20 PM, Monika Jisswel
[EMAIL PROTECTED] wrote:
oops it is reader not Reader (all lower case), so this line : data =
csv.Reader(myfile, delimeter = ',')
should be data = csv.reader(myfile, delimeter = ',')
2008/7/31 S Python [EMAIL PROTECTED]
Hi Everyone,
Thanks for the variety of responses in such a short amount of time.
This distribution list is incredible.
Sorry for the delayed reply as I wanted to test what everyone
suggested, so here goes:
---
@Amin: I tried your suggestion, but perhaps I don't understand your
syntax. Here is what I tried and the resulting error message:
f = open(r'C:\test.txt', 'r')
foo = f.readline.split(',')
Traceback (most recent call last):
File pyshell#16, line 1, in module
foo = f.readline.split(',')
AttributeError: 'builtin_function_or_method' object has no attribute
'split'
Do you know what I did wrong?
---
@Emad, Brett: Thank you for your solutions. They do exactly what I
was looking for.
---
@Chad: Thanks for your suggestion. I think I like it best for its
simplicity.
---
@Emile, Monika, kinuthi: The CSV standard library looks interesting
but I am having mixed results in implementing it. For example, it
works when I try this:
reader = csv.reader(open(r'c:\test.txt', 'rb'))
for row in reader:
print row
['aaa', 'bbb', 'ccc']
but it fails when I try:
import csv
myfile = open(r'c:\test.txt', 'r')
data = csv.Reader(myfile, delimeter = ',')
Traceback (most recent call last):
File pyshell#26, line 1, in module
data = csv.Reader(myfile, delimeter = ',')
AttributeError: 'module' object has no attribute 'Reader'
The error looks similar to what I received when I tried Amin's
approach. Am I missing something?
---
It's interesting to note that for the solutions to work correctly, I
had to remove the quotation marks from the input file.
Thanks again to EVERYONE who took the time to respond. I appreciate your
help.
Samir
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Re: [Tutor] Reading List from File
Emile, Amin: Thank you both for your replies. I was able to get it
working using:
f = open(r'c:\test.txt', 'r')
foo = f.readline().split(',')
Samir
On Thu, Jul 31, 2008 at 3:00 PM, [EMAIL PROTECTED] wrote:
Emile is rigth, there should be a () there.
I'm sorry, im writing this from my cellphone and there's not a pc around XD.
I didn,t know about the csv module either and had to do over complicated
things to deal with embedded commas, thx for that too :).
--
Amin Rainmaker
-- Forwarded message --
From: Emile van Sebille [EMAIL PROTECTED]
To: tutor@python.org
Date: Thu, 31 Jul 2008 11:34:56 -0700
Subject: Re: [Tutor] Reading List from File
S Python wrote:
f = open(r'C:\test.txt', 'r')
foo = f.readline.split(',')
readline is the function/method name
readline() executes that function/method and returns a value
try typing in 'type(f.readline)' vs 'type(f.readline())'
you can't .split() a function but you may split its return value.
but it fails when I try:
import csv
myfile = open(r'c:\test.txt', 'r')
data = csv.Reader(myfile, delimeter = ',')
Python is case sensitive -- reader is different from Reader.
HTH,
Emile
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Re: [Tutor] (no subject)
Hi Morgan, Have you installed Python on your computer? If you are using Microsoft Windows, you can download and install Python from here: http://python.org/download/releases/2.5.2/ and select python-2.5.2.msi. Once it's installed, you should have a directory on your machine called C:\python25. If you save your program with a .py extension in that folder (for example, call it morgan.py), then all you have to do is open a command window (Start Run and enter cmd), go to the C:\python25 directory, and type: python morgan.py Personally, if you are just staring out to program, I would recommend using the Python shell that comes with the package I referred to. Alan's tutorial, found here: http://www.freenetpages.co.uk/hp/alan.gauld/ is very helpful, as is this site, which is what I used to start learning Python: http://hkn.eecs.berkeley.edu/~dyoo/python/idle_intro/ Hope that helps. Good luck! Samir On Tue, Jul 29, 2008 at 7:27 AM, Morgan Thorpe [EMAIL PROTECTED]wrote: Hello. I'm am very new to the whole programming sence. I am trying to catch on but as soon as i want to write a program i've been told to use like 'notepad' in windows XP and save it as a .py file i have gotten this far. Am i wrong so far? If i am right why is it that i can't run it in anyway besides it opening in 'notepad' i've tried opening with Python but it doesn't work. Thanks, Morgan -- This message has been scanned for viruses and dangerous content by the BCEC Security Gateway, and is believed to be clean. Brisbane Catholic Education however gives no warranties that this e-mail is free from computer viruses or other defects. Except for responsibilities implied by law that cannot be excluded, Brisbane Catholic Education, its employees and agents will not be responsible for any loss, damage or consequence arising from this e-mail. ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor ___ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
