Python流程控制 if / for/ while

在Python中没有switch语句

If语句

if condition:

do sth

elif condition:

Do sth

else:

Do sth

while语句有一个可选的else从句

while condition:

do sth

else:

do sth

for循环

for i in range(1, 5):     # 即序列[1, 2, 3, 4]

print i

else:

print ‘The for loop is over‘

break语句

如果你从for或while循环中 终止 ，任何对应的循环else块将不执行。

try..except语句处理异常

import sys

try:

s = raw_input(‘Enter something --> ‘)

except EOFError:

print ‘\nWhy did you do an EOF on me?‘

sys.exit() # exit the program

except:

print ‘\nSome error/exception occurred.‘

# here, we are not exiting the program

print ‘Done‘

可以使用raise语句 引发 异常，相当于java中的throw

Python流程控制 if / for/ while