Python3 basics-for loop

for statement

The Python for loop can traverse any sequence of items, such as a list or a string.

The general format of the for loop is as follows:

for <variable> in <sequence>: <statements> else: <statements>

Example 1: Simple for statement

#!/usr/bin/python3
#-*- coding: utf-8 -*-
lauguages = ["c","java","asp","python"]
for i in lauguages:
    print(i)

Example 2: for...else

#!/usr/bin/python3
#-*- coding: utf-8 -*-
lauguages = ["c","java","asp","python"]
for i in lauguages:
    print(i)
    if i == "python":
        print("终于找到java")
        break
    print("继续循环" +i)
else:
    print("没有循环数据")
print("循环完成")

Example 3: range() function

If you need to traverse a sequence of numbers, you can use the built-in range() function. It will generate a sequence of numbers, for example:

#!/usr/bin/python3
#-*- coding: utf-8 -*-
for i in range(100):
    i=i+1
    print(i)

#!/usr/bin/python3
#-*- coding: utf-8 -*-
language = ["c","java","asp","python"]
for i in language:
    print(i)
for c in range(len(language)):
    print(c,language[c])
#使用range指定区间的值：
for d in range(10,15):
    print(d)
#使range以指定数字开始并指定不同的增量(甚至可以是负数，有时这也叫做'步长'):
for d in range(10,20,2):
    print("开始",d)