1、if条件选择

# coding:utf-8
num = 23
if num>2:
print("dayu")
if num<2:
print("xiaoyu")
## if else
if num>10:
print("D")
else:
print("A")
## if elif else
if num < 10:
print("D")
elif num < 20:
print("C")
elif num < 30:
print("B")
else:
print("A")
## if 嵌套
if num > 10:
if num>20:
if num >30:
print("A")
else:
print("B")
else:
print("C")
else:
print("D")

2、for循环

# coding:utf-8
# Author:Yang Xiaopeng
for i in (1,2,3,4,5,6,7,8):
if i < 8:
print(i,end="____")
else:
print(i)
list1 = [1,2,3,4,5,6]
for item in list1:
if item / 2 == 1:
print(item)
for item in "asjhlafjhkllsadk":
if item == 'k':
print(item)
else:
print(item,end="_")

3、while循环

# coding:utf-8
# Author:Yang Xiaopeng
# 死循环
"""
while True:
pass
"""
num = 1
while num<10:
print(num,end="_")
num+=1

4、break 及 continue

• break: 结束循环
• continue 退出本轮循环，继续下一轮循环

# coding:utf-8
# Author:Yang Xiaopeng
num = 0
while num<10:
num += 1
if num <=6:
continue
print(num, end="_")
print("")
num =0
while num<10:
num = num + 1
if num == 6:
break
print(num, end="_")