#循環 變量 迭代 都是一個意思
#把列表裏面的元素意義的拿出來就是遍歷
listvar = ["one","two","three","four","five","six"]
#用len獲取列表的長度
res = len(listvar)
print(res)spa
例:
i = 0
while i < len(listvar):
# "0 1 2 3 4 5"
res = listvar
print(res)
i+=1
setvar = ["one","two","three","four","five","six"]
#while 循環有它的侷限性,不可以變量集合這樣的數據類型
#因此for循環應用而生 特指用來遍歷的
'''
i = 0
while i < len(setvar):
res = setvar[i]
print(res)
i+=1
'''對象
代碼解析:
把容器類型數據裏面的每個元素,後期咱們還學迭代器 生成器 range對象
for 變量 in 可迭代的對象:
print(變量)
代碼解析:
把容器類型數據類目的每個元素,依次的拿出來賦值變量i
知道全部數據依次遍歷完畢退出循環
#遍歷列表
container = ["one","two","three","four","five","six"]
#遍歷元組
container =("one","two","three","four","five","six")
#遍歷集合
container = {"one","two","three","four","five","six"}
#遍歷字典
container ={'top':'劍聖','middle':'狐狸','bottom':'德萊文'}
#變量字符串
container = "我愛你親愛的菇涼,見到你我就心慌"
for i in container:
print(i)three
listvar = [("王林","王思思","王美麗"),["馬雲","馬花","馬思"],["王寶","馬寶","宋小寶"] ]
#變量的解包
a,b = 1,2
print(a,b)
a,b =[3,4]
print(a,b)
a,b = {5,6}
print(a,b)
print("7777777777777777777777777777")
for a,b,c in listvar:
"""
a,b,c ("王林","王思思","王美麗")
a,b,c ["馬雲","馬花","馬思"]
a,b,c ["王寶","馬寶","宋小寶"]
"""
print(a,b,c)
listvar = [(1,2),[3,4],[5,6]]
for a,b in listvar:
print(a,b)字符串
listvar = [("王林","王思思"),["馬花","馬美麗"],["王寶","宋小寶"] ]
for i in listvar:
for j in i :
print(j)class
#語法:
range(start,end,step)
start : 開始值
end :結束值
step:步長
使用方式和切片語法相似,高位end那個值取不到,取到end以前的那個值
#1個參數的狀況 range(5) => 0 1 2 3 4 默認0開始 高位5取不到,最大取到4
print(range(5),type(res))
res = list(range(5))
print(res)
for i in range(5):
print(i)
#2個參數的狀況
for i in range(3,10):
print(i)
#(33個參數的狀況 2 4 6 8 10
#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)容器
if 5 == 5:
pass
i = 0
while i < 10:
pass #約定俗成,在循環裏面什麼也不行的狀況下,給予友好提示
i+=1變量
(只能用於循環當中)
'''打印1~10,若是遇到5終止循環'''
i=1
while i <=10:
if i == 5:
break
print(i)
i+=1
#break 終止當前循環,外面循環一次,裏面循環三次,只不過當j=3的時候,循環終止了
i = 1
while i<=3:
j = 1
while j<=3:
if j == 3:
break
print(i,j)
j+=1
i+=1
#1,1 1,2 2,1 2,2 3,1 3,2循環
例:遍歷
#打印1~10 不打印5
i = 1
while i <= 10:
if i == 5:
i +=1 #要當心跳過循環以後,後面的代碼不執行,從循環開始在執行
continue
print(i,end=" ") #讓它打印一行而且空格
i+=1數據類型
例:
#打印1~100 全部不含4的數字
#解析:
98 若是取出98的各位數和十位數
8 => 98 % 10 => 8
9 =>98 // 10 => 9
經過地板除 // 能夠得到一個數的高位
經過取餘 % 能夠獲取一個數的低位
#第一個方法
i = 1
while i<100:
if i // 10 == 4 or i % 10 == 4:
i += 1
continue
print(i)
i+=1
#第二個方法i=1while i <= 100: num = str(i) if '4' in num: i+=1 continue print(i) i+=1