python39.dll not found
Please someone help me to find the solution for the problem Whenever I am trying to run python idle after installing, it is showing me- [1]python.exe - Syntax Error The code execution cannot proceed because [2]python39.dll was not found. Re-installing the program may fix the problem. References Visible links 1. http://python.exe/ 2. http://python39.dll/ -- https://mail.python.org/mailman/listinfo/python-list
Re: How to pass a method as argument?
On 9/29/21 23:11, Anil Anvesh wrote: I want to write a python calculator program that has different methods to add, subtract, multiply which takes 2 parameters. I need to have an execute method when passed with 3 parameters, should call respective method and perform the operation. How can I achieve that? let me add - this is probably not the place you are in your Python learning, so don't worry about this, but the operator module is designed for these kind of usages, when you want to pass an operator like + - etc. but of course can't pass the op itself to take actions because it's not a callable - the operator module has callables that can be used. -- https://mail.python.org/mailman/listinfo/python-list
Re: How to pass a method as argument?
On 30/09/2021 18.11, Anil Anvesh wrote:
> I want to write a python calculator program that has different methods to
> add, subtract, multiply which takes 2 parameters. I need to have an execute
> method when passed with 3 parameters, should call respective method and
> perform the operation. How can I achieve that?
>
>
>
> class calc():
> def __init__(self,a,b):
> self.a=a
> self.b=b
>
> def ex(self,fun):
> self.fun=fun
> if fun=="add":
> self.add()
>
> def add(self):
> return self.a+self.b
> def sub(self):
> return self.a-self.b
> def mul(self):
> return self.a*self.b
> def div (self):
> return self.a/self.b
> def execu(
> obj1=calc()
> obj1.execu("add",1,,2)
>
This is a common course-assignment.
NB the code-examples below are incomplete. You may need to research
these techniques further, and thus learn how 'it' all fits-together
(I set 'homework' rather than doing it!)
There are several techniques which can be employed and/or combined here.
1 if-elif 'ladder'
2 dict[ionary] as select/case construct
3 functions as 'first-class objects'
The basic problem is to take a 'command' which is formatted as a
str[ing], and decide which of several options to choose:
1 if-elif is a simple and easy-to-read solution:
if command == "add":
do_this...
elif command == "sub":
do_that...
...
else:
# oops: "I'm afraid I can't do that, Dave"
# don't forget to add a 'catch-all' to handle user-error!
2 using a dict is shorter and avoids some of the 'boiler-plate'
repetition which causes many of us to rebel against using the above. We
use the command received from the user as a key into the dict.
3 a function and/or its name is as much data as the 'variable' "command"
or indeed the str-constant "add" - once it has been defined! Thus it is
possible to treat functions like anything else:
data_as_string = "my string"
# can be likened to:-
def my_function(): pass
data_as_function = my_function
Note that (like most else), the function must be defined before it can
be 'used'!
Returning to the stated-problem:
def add( etc ): ...
then using the if-elif 'ladder' above as a framework create a dict which
'links' the input command (as str) to the applicable function:
calculator = { "add": add,
"sub": sub,
# indeed we can become rather more 'creative'
"+" " add,
...
}
Thereafter, we can apply the dict to solve the problem:
calculator.get( command,
"Error message/advice, eg mentioning add, or + etc"
)
NB it has been left to you to perfect the technique so that the value(s)
to be calculated are properly communicated to the chosen function.
PS you may find the Python-Tutor Discussion List helpful
--
Regards,
=dn
--
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RE: How to pass a method as argument?
Sounds like an excellent homework question.
But your method of using an object is not what first comes to mind based on
your cursory description.
There is a python idiom using functional programming that looks like this:
def doit(a, b, fun): return(fun(a,b))
So make up your own functions like:
def addit(a,b): return(a+b)
And make up others doing multiply and whatever and call something like this:
doit(3,5, addit)
Now if you want a user to put in text like "add" that is another story. If
you want this in the context of an object, ditto.
-Original Message-
From: Python-list On
Behalf Of Anil Anvesh
Sent: Thursday, September 30, 2021 1:11 AM
To: python-list@python.org
Subject: How to pass a method as argument?
I want to write a python calculator program that has different methods to
add, subtract, multiply which takes 2 parameters. I need to have an execute
method when passed with 3 parameters, should call respective method and
perform the operation. How can I achieve that?
class calc():
def __init__(self,a,b):
self.a=a
self.b=b
def ex(self,fun):
self.fun=fun
if fun=="add":
self.add()
def add(self):
return self.a+self.b
def sub(self):
return self.a-self.b
def mul(self):
return self.a*self.b
def div (self):
return self.a/self.b
def execu(
obj1=calc()
obj1.execu("add",1,,2)
--
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--
https://mail.python.org/mailman/listinfo/python-list
Re: Definitive guide for Regex
> On 30 Sep 2021, at 19:35, dn via Python-list wrote: > > On 01/10/2021 06.16, Barry Scott wrote: >> >> >>> On 30 Sep 2021, at 12:29, Shaozhong SHI wrote: >>> >>> Dear All, >>> >>> I am trying to look for a definitive guide for Regex in Python. >>> Can anyone help? >> >> Have you read the python docs for the re module? > > > I learned from Jeffrey Friedl's book "Mastering Regular Expressions", > but that was in a land far away, last century, and under a different > language (and the original version - I see it's now up to its third > edition). > > Despite their concise exercise of power (and the fact that in my > Python-life I've never been put into a corner where I absolutely must > use one), I'm no longer a fan... Agreed, regex is the last tool I reach for in python code. I find I use split() a lot to break up strings for processing. But there are cases where a regex is the best tool for a particular job and I then use the re module. But it costs in maintainability. I speak as the author of a regex engine and know how to write scary regex's when the need arises. Barry > -- > Regards, > =dn > -- > https://mail.python.org/mailman/listinfo/python-list > -- https://mail.python.org/mailman/listinfo/python-list
Re: Definitive guide for Regex
On 01/10/2021 06.16, Barry Scott wrote: > > >> On 30 Sep 2021, at 12:29, Shaozhong SHI wrote: >> >> Dear All, >> >> I am trying to look for a definitive guide for Regex in Python. >> Can anyone help? > > Have you read the python docs for the re module? I learned from Jeffrey Friedl's book "Mastering Regular Expressions", but that was in a land far away, last century, and under a different language (and the original version - I see it's now up to its third edition). Despite their concise exercise of power (and the fact that in my Python-life I've never been put into a corner where I absolutely must use one), I'm no longer a fan... -- Regards, =dn -- https://mail.python.org/mailman/listinfo/python-list
python.exe - System Error
please guide me to out from this difficulties, whenever I'm trying to install python idle it is showing me the error called [1]python.exe - System Error I have tried couple of ways to get rid out of this but failed every time, please please help me to find the exact solution for this problem. Thank You References Visible links 1. http://python.exe/ -- https://mail.python.org/mailman/listinfo/python-list
Re: Definitive guide for Regex
> On 30 Sep 2021, at 12:29, Shaozhong SHI wrote: > > Dear All, > > I am trying to look for a definitive guide for Regex in Python. > Can anyone help? Have you read the python docs for the re module? Barry > > Regards, > > David > -- > https://mail.python.org/mailman/listinfo/python-list > -- https://mail.python.org/mailman/listinfo/python-list
Re: How to pass a method as argument?
Please help me to out from this difficulties, whenever I'm trying to install python idle it is showing me the error called "[1]python.exe - System Error"** I have tried couple of ways to get rid out of this but failed every time, please please help me to find the exact solution for this problem. Thank You Sent from OPPO Mail On Edmondo Giovannozzi , 30 Sep 2021 20:34 wrote: References Visible links 1. http://python.exe/ -- https://mail.python.org/mailman/listinfo/python-list
Re: How to pass a method as argument?
Il giorno giovedì 30 settembre 2021 alle 07:11:28 UTC+2 anila...@gmail.com ha
scritto:
> I want to write a python calculator program that has different methods to
> add, subtract, multiply which takes 2 parameters. I need to have an execute
> method when passed with 3 parameters, should call respective method and
> perform the operation. How can I achieve that?
>
>
>
> class calc():
> def __init__(self,a,b):
> self.a=a
> self.b=b
>
> def ex(self,fun):
> self.fun=fun
> if fun=="add":
> self.add()
>
> def add(self):
> return self.a+self.b
> def sub(self):
> return self.a-self.b
> def mul(self):
> return self.a*self.b
> def div (self):
> return self.a/self.b
> def execu(
> obj1=calc()
> obj1.execu("add",1,,2)
For example:
|def ex(self, fun):
|getattr(self, fun)()
--
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How to pass a method as argument?
I want to write a python calculator program that has different methods to add,
subtract, multiply which takes 2 parameters. I need to have an execute method
when passed with 3 parameters, should call respective method and perform the
operation. How can I achieve that?
class calc():
def __init__(self,a,b):
self.a=a
self.b=b
def ex(self,fun):
self.fun=fun
if fun=="add":
self.add()
def add(self):
return self.a+self.b
def sub(self):
return self.a-self.b
def mul(self):
return self.a*self.b
def div (self):
return self.a/self.b
def execu(
obj1=calc()
obj1.execu("add",1,,2)
--
https://mail.python.org/mailman/listinfo/python-list
Re: XLRDError: Unsupported format, or corrupt file: Expected BOF record; found b'\r\n\r\n\r\n\r\n'
On Thursday, September 30, 2021 at 9:20:37 AM UTC+8, hongy...@gmail.com wrote:
> On Thursday, September 30, 2021 at 5:20:04 AM UTC+8, Peter J. Holzer wrote:
> > On 2021-09-29 01:22:03 -0700, hongy...@gmail.com wrote:
> > > I tried to convert a xls file into csv with the following command, but
> > > failed:
> > >
> > > $ in2csv --sheet 'Sheet1' 2021-2022-1.xls
> > > XLRDError: Unsupported format, or corrupt file: Expected BOF record;
> > > found b'\r\n\r\n\r\n\r\n'
> > >
> > > The above testing file is located at here [1].
> > >
> > > [1] https://github.com/hongyi-zhao/temp/blob/master/2021-2022-1.xls
> > Why is that file name .xls when it's obviously an HTML file?
> Good catch! Thank you for pointing this out. This file is automatically
> exported from my university's teaching management system, and it was assigned
> the .xls extension by default.
According to the above comment, after I change the extension to html, the
following python code will do the trick:
import sys
import pandas as pd
if len(sys.argv) != 2:
print('Usage: ' + sys.argv[0] + ' input-file')
exit(1)
myhtml_pd = pd.read_html(sys.argv[1])
#In [25]: len(myhtml_pd)
#Out[25]: 3
for i in myhtml_pd[2].index:
if i > 0:
for j in myhtml_pd[2].columns:
if j >1 and not pd.isnull(myhtml_pd[2].loc[i][j]):
print(myhtml_pd[2].loc[i][j])
HZ
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python.exe - System Error
Hello Sir/Madam, please help me to out from this difficulties, whenever I'm trying to install python idle it is showing me the error called "[1]python.exe - System Error"** I have tried couple of ways to get rid out of this but failed every time, please please help me to find the exact solution for this problem. Thank You. References Visible links 1. http://python.exe/ -- https://mail.python.org/mailman/listinfo/python-list
Definitive guide for Regex
Dear All, I am trying to look for a definitive guide for Regex in Python. Can anyone help? Regards, David -- https://mail.python.org/mailman/listinfo/python-list
