python 异常处理
python">def main():
try:
for line in readfile('lines.txt'): print(line.strip())
except IOError as e:
print('could not open the file:',e)
except ValueError as e:
print('bad filename:',e)
def readfile(filename):
if filename.endswith(".txt"):
fh = open(filename)
return fh.readlines()
else: raise ValueError("file must be ends with .txt")
if __name__ == "__main__": main()