Strange location for a comma
Peter Otten
__peter__ at web.de
Thu Sep 3 08:48:03 EDT 2015
ast wrote:
>
> "ast" <nomail at invalid.com> a écrit dans le message de
> news:55e83afb$0$3157$426a74cc at news.free.fr...
>> Hello,
>> At the end of the last line of the following program,
>> there is a comma, I dont understand why ?
>>
>> Thx
>>
>>
>> from cx_Freeze import setup, Executable
>>
>> # On appelle la fonction setup
>> setup(
>> name = "salut",
>> version = "0.1",
>> description = "Ce programme vous dit bonjour",
>> executables = [Executable("salut.py")], # <--- HERE
>> )
>>
>>
>
> Ok its understood, it's a 1 element only tuple
>
> example:
>
>>>> A = 5,
>>>> A
> (5,)
>
>>>> A = (6)
>>>> A
> 6
>
No, in a function call an extra comma has no effect:
>>> def f(x): return x
...
>>> f(42)
42
>>> f(42,)
42
>>> f(x=42)
42
>>> f(x=42,)
42
The only reason I see to add an extra comma are smaller and easier to read
diffs when you make a change:
$ cat before.py
func(
arg_one=1,
arg_two=2
)
func(
arg_one=1,
arg_two=2,
)
$ cat after.py
func(
arg_one=1,
arg_two=2,
arg_three=3
)
func(
arg_one=1,
arg_two=2,
arg_three=3,
)
$ diff -u before.py after.py
--- before.py 2015-09-03 14:44:27.709735075 +0200
+++ after.py 2015-09-03 14:44:55.275958331 +0200
@@ -1,9 +1,11 @@
func(
arg_one=1,
- arg_two=2
+ arg_two=2,
+ arg_three=3
)
func(
arg_one=1,
arg_two=2,
+ arg_three=3,
)
More information about the Python-list
mailing list