打印每个功能的输出

Question

Using a save_ouput function, how can I save the output of every function?

def a():
    print("abc,")

def b():
    print("help,")

def c():
    print("please")

def save_output():
    # save output of all functions

def main():
    a()
    b()
    c()
    save_output()

main()

^So it'd save abc,help,please as a text file when main is called

Answer 1

You can't with your current structure, at least not without something crazy like inspecting the terminal (which might well not exist).

The right way to do this is by redirecting standard out before you call the other functions:

import sys
def a():
  print("abc,")
def b():
  print("help,")
def c():
  print("please")

def main():
 original_stdout = sys.stdout
 sys.stdout = open('file', 'w')
 a()
 b() 
 c()
 sys.stdout = original_stdout

main()
# now "file" contains "abc,help,please"

However, it's also worth asking why you want to do this at all – there are many more straightforward ways to write to a file that don't involve messing with stdout, which might have unintended consequences. Can you describe your use case a little more fully?

Answer 2

Would you consider something like this

def a():
    return 'abc'
def b():
    return 'help'
def c():
    return 'please'
def save_output(file_name, *args):
    with open(file_name, 'w') as f:
        for x in args:
            f.write('Function {0}() returned: {1}{2}'.format(x.__name__,x(),'\n'))

To test:

save_output('example.txt',a,b,c)

Output:

Function a() returned: abc
Function b() returned: help
Function c() returned: please