Python ImportError- what is wrong here?

问题

I am new to programming and Python. I am following the Learn Python the Hard Way book. As a part of exercise 25, I wrote a script:

def break_words(stuff):   
    """This function will break up words for us."""   
    words = stuff.split(' ')    
    return words        

def sort_words(words):    
    """Sorts the words."""    
    return sorted(words)        

def print_first_word(words):    
    """Prints the first words after popping it off."""    
    word = words.pop(0)    
    print word

def print_last_word(words):    
    """Prints the last word after popping it off."""    
    word = words.pop(-1)    
    print word    

def sort_sentence(sentence):    
    """Takes in a full sentence and returns the sorted words."""    
    words = break_words(sentence)    
    return sort_words(words)       

def print_first_and_last(sentence):    
    """Prints the first and last words of the sentence."""    
    words = break_words(sentence)    
    print_first_word(words)`

I saved this from gedit as

ex25.py

under the path

C:\Users\Brandon\Experiment\Python_ex

I am running 64-bit Windows 7.

When I go to import ex25 from python.exe I get:

> Traceback (most recent call last):
>  File "(stdin)", line 1, in `<module>`
> ImportError: No module named ex25

Under Computer\Properties\Advanced\Environment Variables I added the System Variable:

PYTHONPATH

C:\Python27

That didn't help. What am I doing wrong?

回答1:

C:\Users\Brandon\Experiment\Python_ex is not on your system path, thus python is not aware where your ex25 module can be found

import sys
sys.path.append(r'C:\Users\Brandon\Experiment\Python_ex')

回答2:

I just had the same problem. As my file was saved in Desktop/mint/ex25.py . I first changed the directory to desktop by command cd Desktop/mint. and than run the way it has been recommended. It will solve it. Want to go back to older directory use command cd -.

来源：https://stackoverflow.com/questions/6862214/python-importerror-what-is-wrong-here

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python

import

module

importerror