for循环 | range 对象

# ### for循环
# 循环  遍历 迭代
# 把列表的元素一一的拿出来遍历
listvar = ["黄雄大","黄文","黄仪正","黄少正","黄广雄","黄将用"]
# 用len获取列表的长度
res = len(listvar)
print(res)

#(1) while 的遍历方式

"""
i = 0 
while i < 0 len(listvar):
	'''0 1 2 3 4 5'''
	res = listvar[i]
	print(res)
	i+=1
"""

setvar = {"黄雄大","黄文","黄仪正","黄少正","黄广雄","黄将用"}
#while 循环有它的局限性,不能够遍历集合这样的数据类型,
#所以for 循环应用而生 特指用来遍历的

'''
while i < len(setvar):
	res = setvar[i]
	print(res)
	i+=1
'''

'''
容器类型数据是可迭代对象的一种,后期我们还要学迭代器 生成器 range对象 
for变量 in 可迭代的对象
	print(变量)	
'''

"""
代码解析:
把容器类型里面的每一个元素,依次的拿出来赋给变量i,
直到所有数据依次遍历完毕,退出循环
"""
#遍历列表
container = ["黄雄大","黄文","黄仪正","黄少正","黄广雄","黄将用"]
#遍历元组
container = ("黄雄大","黄文","黄仪正","黄少正","黄广雄","黄将用")
#遍历集合
container = {"黄雄大","黄文","黄仪正","黄少正","黄广雄","黄将用"}
#遍历字典
contaner = {"top":"亚瑟","moddle":"王军","bottom":"黄雄达"}
#遍历字符串 
container = "我爱你,亲爱的滴菇娘,见到你我就心慌"
for i in container:
	print(i)

# (3)遍历等长的二级容器
listvar = [("王建林","王思聪","王美丽"),["马云","马华腾","马美丽"],["王宝强","马蓉","宋小宝"]]
# 变量的解包
a,b = 1,2
print(a,b)
a,b = [3,4]
print(a,b)
a,b ={5,6}
print(a,b)

for a,b,c in listvar:
	'''
	a,b,c = ("王建林","王思聪","王美丽")
	a,b,c = ["马云","马华腾","马美丽"]
	a,b,c = ["王宝强","马蓉","宋小宝"]
	'''
	print(a,b,c)

#(4)遍历不等长的二级容器
listvar = [("王建林","王思聪","王美丽"),["马云","马华腾"],["王宝强"]]
for i in listvar:
	for j in i:
		print(j)

#(5)range 对象
"""
range(start ,end, step)
	start:开始值
	end: 结束值
	step:步长
使用方式和切片语法类似,高位end那个值取不到,取到end之前的那个值
"""
#1个参数的情况,range(5) =>0 1 2 3 4默认从0 开始,高位5 取不到,最大取到4
print(range(5),type(range))
res = list(range(5))
#2个参数的情况

for i in range(3,10):
	print(i)
"""正序"""
for i in range(2,11,2):
	print(i)
'''倒序'''

#打印9~1 9 8 7 6 5 4 3 2 1
for i in range(9,0,-1):
	print(i)

  

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转载自www.cnblogs.com/huangjiangyong/p/10793954.html