Question

I have read the python document about subprocesses, but the argument preexec_fn for subprocess.Popen can only point to a function with no argument.

Now I want to call a function with two arguments just like what preexec_fn does, I’ve tried to use global variables, but it doesn’t work.

How can I do that?

Answer 1

You can pass the arguments using functools.partial or a lambda:

>>> import functools
>>> def need_two_arguments(a,b):
...     print a + b
... 
>>> no_arguments_needed = functools.partial(need_two_arguments, "Hello, ", "World!")
>>> no_arguments_needed()
Hello, World!
>>> no_arguments_needed = (lambda: need_two_arguments("Hello, ", "World!"))
>>> no_arguments_needed()
Hello, World!