python 中的異常處理

import os

if os.path.exists('sketch.txt'):
    data=open('sketch.txt')
    
    for each_line in data:
        if not each_line.find(':')==-1:
            (role,line_spoken)=each_line.split(':',-1)
            print(role,end='')
            print(' said: ',end='')
            print(line_spoken,end='')
            
    data.close()
else:
    print('The data file is missing!')

try:
    data=open('sketch.txt')
    
    for each_line in data:
        try:
            (role,line_spoken)=each_line.split(':',1)
            print(role,end='')
            print(' said: ',end='')
            print(line_spoken,end='')
        except ValueError:
            pass
        
    data.close()
except IOError:
    print('The data file is missing!')

雖然兩種處理方式結果是一樣的，但是複雜性通常不是一個好東西，而第一種方案明顯較爲複雜。

用好try能使代碼更加易讀易懂，而且更容易修改。