Python try/except异常处理机制

1. use try, except, finally

try:
    data=open('its.txt','w')
    print('its..', file=data)
except:
    print('file error:', +str(err))
finally:
    if 'data' in locals():
        data.close()

2. use with as 省略了finally代码

try:
    with open('its.txt','w') as data:
        print('its.....with', file=data)
except IOError as err:
    print('file error:' +str(err))

3. use with as on the example

man = []
other = []
try:
    data = open('sketch.txt')
    for each_line in data:
        try:
            (role, line_spoken) = each_line.split(':',1)
            line_spoken=line_spoken.strip()
            if role== 'Man':
                man.append(line_spoken)
            elif role == 'Other Man':
                other.append(line_spoken)
        except ValueError:
            pass
    data.close()
except IOError:
    print ('The datafiel is missing!')

try:
    with open('man_data.txt','w') as man_file:
        print(man,file=man_file)

    with open('other_data.txt','w') as other_file:
        print(other,file=other_file)

except IOError as err:
    print('file error:' +str(err))