while 循环
while 判断条件(condition):
执行语句(statements)……
#!/usr/bin/env python3
n = 100
sum = 0
counter = 1
while counter <= n:
sum = sum + counter
counter += 1
print("1 到 %d 之和为: %d" % (n,sum))
输出如下:
1 到 100 之和为: 5050
for 循环(可用于遍历一个序列)
for <variable> in <sequence>:
<statements>
else:
<statements>
使用range()
函数进行遍历循环
for i in range(5):
print(i)
输出如下:
0
1
2
3
4
遍历序列
languages = ["C", "C++", "Perl", "Python"]
for x in languages:
print(x)
输出如下:
C
C++
Perl
Python
练习题
练习一
如下,有一个由多个整数子列表构成的母列表,使用循环的方式,计算其中所有数字的和。
t = [[1,2,3], [3,4,5], [7,9,8], [3,4,7,8,9,10,12,13], [1,2], [3], [2,6,8,9], [11,22,4,6,9,11]]
练习二
如下,有一个列表t1,你需要建立一个新列表t2,使得t2中的第i个元素是t1中前i+1个元素的和。
t1 = [1,2,4,6,7,8,9,11,15,16,17,23]
练习三
有如下一个dict,输出所有value不为0的key和value
province_data = {"zhejiang": 3, "jiangsu": 0, "anhui": 0, "jiangxi": 0, "shanghai": 0,"fujian": 0, "guangdong": 0,"guangxi":5, "hainan":0, "hunan":0, "hubei":0, "chongqing":0, "guizhou":0, "sichuan":0, "xizang":0, "qinghai":0, "xinjiang":0, "gansu":0, "ningxia":0, "shananxi":0, "neimenggu":0, "shanxi":0, "henan":0, "hebei":0, "shandong":11, "beijing":9, "tianjin":0, "liaoning":0, "jilin":0, "heilongjiang":0, "taiwan":0, "xianggang":0, "aomen":1,"yunnan":0}