初学Python常见的错误

Traceback (most recent call last):
File "unzip.py", line 20, in <module>
tar = tarfile.open(file)
File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/tarfile.py", line 1658, in open
return func(name, "r", fileobj, **kwargs)
File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/tarfile.py", line 1720, in gzopen
fileobj = bltn_open(name, mode + "b")
TypeError: coercing to Unicode: need string or buffer, type found

#扫描当前目前下所有的gz文件
currDir = os.getcwd()
files = os.listdir(currDir)
dstDir = "201301_09"
if not os.path.exists(dstDir):
os.mkdir(dstDir)
for fileName in files:
if os.path.isfile(fileName) and tarfile.is_tarfile(fileName):
print fileName
try:
tar = tarfile.open(file)#这里应该是fileName而不是file
names = tar.getnames()
for name in names:
tar.extract(name,path=dstDir)
tar.close()
except tarfile.ReadError:
print "not a tarFile"
pass