file类使用出错，怎么回事？
程序代码：
def TT():
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
出错如下：程序代码：>>> TT()
Traceback (most recent call last):
File "<pyshell#30>", line 1, in <module>
TT()
File "<pyshell#29>", line 9, in TT
f = file('poem.txt', 'w') # open for 'w'riting
NameError: global name 'file' is not defined今天学了下python，定义了个TT函数，为什么一运行TT()就出现file未定义这个错误？，难道file类还要import?那么要import什么？
[ 本帖最后由 zjsxwc 于 2012-5-4 16:02 编辑 ]
