如何在python提示符下从函数打印变量

Question

There are various python files in a directory and all these contain a function desciption() as follows :

def description():
    desc = 'something'
    return desc

Now I have main.py as follows :

def a():
    pth = os.listdir('homedir/workspace')
    for filename in pth :
        exec "import " + filename
        desc = eval(filename + '.desciption()')
    print desc

Right now when I run python main.py, nothing happens. How do I print this desc when I run python main.py? Thanks in advance!

Answer 1

Assuming the import worked, and that you have imported a module called filename in each iteration, then you could get the module by name, and call its descrpition() method:

import sys
mod = sys.modules[filename]
print mod.description()

But note that it may make more sense to print the module's pydocs:

print mod.__doc__

Answer 2

You didn't close quotes properly in this line:

pth = os.listdir('homedir/workspace)

Also you should not use eval here:

desc = eval(filename + '.desciption()')

and I assume you wanted to import by variable here:

        exec "import " + filename

This is how it should look like:

def a():
    import importlib

    pth = os.listdir('homedir/workspace')
    for filename in pth :
        mdl = importlib.import_module(os.path.splitext(filename)[0])
        desc = mdl.description()
        print desc

see https://docs.python.org/2/library/importlib.html#importlib.import_module

https://docs.python.org/2/library/os.path.html#os.path.splitext

Answer 3

1. You missed the closing ' in the pth variable
2. You've referenced desc on the last line without declaring it first.
   Start your function with desc = None

Answer 4

def a():
    pth = os.listdir('homedir/workspace')

    for filename in pth:
        module_name = os.path.splitext(filename)[0]
        exec "import " + module_name
        desc = eval(module_name + '.description()')
        print desc

make sure the main.py located at the same path with your modules. or add it to sys path by

import sys
sys.path.append(r"homedir/workspace")