50.基础语法-循环

for循环

• 遍历可迭代的类型
• 把其中元素依次去除

l = [1,2,3,4,5,9,8]
for a in l:
    print(a)

while循环

#本金10000元，利率6.7%，问存多少年大于20000
#不论while中是不是执行，else中的语句都要执行

bj = 10000
year = 0
while bj < 20000:
    bj = bj * (1 + 0.067)
    year += 1
else:
    print(year)

continue用法

• 用法一

l = [1,2,3,4,5,6,7,8,9,10]
for a in l:
    if a % 2 == 0:
        print(str(a) + "  是个双数")
    else:
        continue

• 用法二

l = [1,2,3,4,5,6,7,8,9,10]
for a in l:
    if a % 2 ==1:
        continue
    print(str(a) + "  是个双数")

len()用法

• 返回对象（字符、列表、元组等）元素个数

s = "abcde"
for i in range(len(s)):
    print(s[i])