import os

if os.path.exists('sketch1.txt'): #使用if 来对文件是否存在进行逻辑判断

data = open ('sketch1.txt')

for each_line in data:

if each_line.find(':')>0:

(role,line_spoken) = each_line.split(':',1)

print(role ,end ='')

print(' said: ',end ='')

print(line_spoken,end='')

else:

print (each_line,end='')

data.close()

else:

print('Data file is missing!')

print('\n------------------------------------')#使用try来尝试文件是否存在

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 ('Data file is missing!')

print('\n------------------------------------')

print (os.getcwd())

data = open('sketch.txt')

print (data.readline(), end='')

data.seek(0) #Go back to the 1st line

for each_line in data:

print(each_line, end='')

print('\n------------------------------------')

data.seek(0) #Go back to the 1st line

for each_line in data:

if each_line.find(':') > 0:

(role, line_spoken) = each_line.split(':',1)

print (role ,end='')

print (' said: ', end='')

print (line_spoken, end='')

else:

print (each_line, end='')

print('\n------------------------------------')

data.seek(0)

for each_line in data:

try: # try to split each_line, if get exception print the whole line

(role, line_spoken) = each_line.split (':',1)

print (role ,end='')

print (' said: ', end='')

print (line_spoken, end='')

except:

#pass # pass: you can pass the exception

print (each_line, end='')

data.close()