python学习笔记

1.if语句（python中没有switch语句，可用if……elif……else代替）

格式：

　　if 表达式：

　　　　#语句

　　else：

　　　　#语句

eg：

number = 23
guess = int(raw_input('Enter an integer:'))

if guess == number:
    print'Congratulations'
    print'but you do not win any prizes!'
elif guess < number:
    print'No,it is higher'
else:
    print'NO,it is lower'
print'Done'

2.while语句

格式：

while <test>:

　　#语句

else：#可跟else从句

eg:

number = 23
running = True

while running:
    guess = int(raw_input('Enter an integer:'))
    if guess == number:
        print'Congratulations'
        running = False
    elif guess < number:
        print'it is higher'
    if guess > number:
        print'it is lower'
else:
    print'The while loop is over.'

print'Done'

 

3.for语句格式：

for <var> in range(<begin>,<end>):

　　#语句

for i in range(1,5):
    print i
else:
    print "The for loop is over"