??12?? ????/???

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??????????????????????????????????????????????????????????????????????Щ?????????????????raw_input??print??????????Щ????????????????????????????????str??????????????磬????????rjust?????????????????????????????????????help(str)?????????顣

??????????????/???????????????????????????д?????????????????????????????????????????????????Щ?????

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???????????????file????????????????????????file???read??readline??write????????????д?????????????д?????????????????????????????????????????????????????????close??????????Python?????????????????á?

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??12.1 ??????

#!/usr/bin/python
# Filename: using_file.py

poem = '''\
Programming is fun
When the work is done
if you wanna make your work also fun:
        use Python!
'''

f = file('poem.txt', 'w') # open for 'w'riting
f.write(poem) # write text to file
f.close() # close the file

f = file('poem.txt')
# if no mode is specified, 'r'ead mode is assumed by default
while True:
    line = f.readline()
    if len(line) == 0: # Zero length indicates EOF
        break
    print line,
    # Notice comma to avoid automatic newline added by Python
f.close() # close the file

????????code/using_file.py??

???

$ python using_file.py
Programming is fun
When the work is done
if you wanna make your work also fun:
        use Python!

????ι???

??????????????????????????????????????????file?????????????????????'r'????д????'w'???????????'a'???????????ж??????????????????????help(file)?????????????顣

??????????д???????????????file???write??????д??????????????close???????????

????????????????δ????????????????????????????????????????????????????????????У????????readline??????????????С?????????????????????з???????????С??????????? ??? ?????????????????????????????????????????????????

????????????????????????????з???β????????????print???????????????????????С??????????close???????????

????????????poem.txt???????????????????????????????