python，从其他目录下的文件导入当前文件夹下的文件

Question

I have a package which intends to import a file that user (me) provides

In c:\\lib \\calc.py

# some codes to find which file to import
filename = "A"
__import__(filename)
...

And I have a file c:\\scripts \\A.py

Note A.py is in a different folder than calc.py. Now I'm supposed to do this under command window

cd C:\scripts
python c:\lib\calc.py

but I get an error message

No module named A

A.py is in the current folder, why does python fail to find it? How can I make A.py available?

Thanks.

Answer 1

You can add the path to your scripts directory in your script calc.py so it can find the A.py module.

import sys
sys.path.append('C:\scripts')

Answer 2

If you are on Python version 2.7 or newer you can use the importlib package. The import_module function can accept an absolute path which, IIRC, does not need to be on your PYTHONPATH.

import importlib
mod = importlib.import_module(filepath)

Or, if you wanted to manually do the work yourself (or if you are using Python 2.6 or earlier), you can use the imp package directly:

import imp
mod = imp.load_module(imp.find_module(filename, filepath))