十年網(wǎng)站開(kāi)發(fā)經(jīng)驗(yàn) + 多家企業(yè)客戶(hù) + 靠譜的建站團(tuán)隊(duì)
量身定制 + 運(yùn)營(yíng)維護(hù)+專(zhuān)業(yè)推廣+無(wú)憂(yōu)售后,網(wǎng)站問(wèn)題一站解決
一。while 循環(huán)
1.循環(huán):重復(fù)做某件事
在木蘭等地區(qū),都構(gòu)建了全面的區(qū)域性戰(zhàn)略布局,加強(qiáng)發(fā)展的系統(tǒng)性、市場(chǎng)前瞻性、產(chǎn)品創(chuàng)新能力,以專(zhuān)注、極致的服務(wù)理念,為客戶(hù)提供成都網(wǎng)站建設(shè)、網(wǎng)站建設(shè) 網(wǎng)站設(shè)計(jì)制作按需求定制制作,公司網(wǎng)站建設(shè),企業(yè)網(wǎng)站建設(shè),高端網(wǎng)站設(shè)計(jì),營(yíng)銷(xiāo)型網(wǎng)站,成都外貿(mào)網(wǎng)站建設(shè)公司,木蘭網(wǎng)站建設(shè)費(fèi)用合理。
2.語(yǔ)法
while 條件:
code1
3.結(jié)束while的方式:
1.條件不滿(mǎn)足,下次循環(huán)開(kāi)始時(shí)判斷
2.break直接結(jié)束本層循環(huán)
4.while + continue
continue 之后的代碼不會(huì)運(yùn)行了,直接開(kāi)始下次循環(huán)
n= 0
while n < 6:
if n == 4:
n+=1
continue
else:
print(n)
n+=1
5.while循環(huán)嵌套
while:
while:
while:
break
break
break
count = 1
tag = True
while tag:
name = input("name: ")
passwd = input("passwd ")
if count == 3:
print("too many")
break
if name == "chad" and passwd == "123":
print("successfull")
while tag:
print("""
1
2
3
""")
cho = input("choice:")
if cho == "1":
print(1)
elif cho == "2":
print(2)
else:
print(3)
tag = False
else:
print("error")
count +=1
6. while + else
如果while循環(huán)沒(méi)有被break打斷,才會(huì)執(zhí)行
循環(huán)要正常結(jié)束
count = 0
while count < 3:
print(count)
count += 1
else:
print("run")
二。for 循環(huán)
循環(huán)取值簡(jiǎn)潔
for+brek
for+continue
for+else
dic = {"name":"sdfa","age":23}
for i in dic:
print(i,dic[i])
返回字符串
dic = {"name":"sdfa","age":23}
for i,r in dic.items():
print(i,r)
以字符串返回key和value
dic = {"name":"sdfa","age":23}
for i in dic.items():
print(i)
以元組返回key和value,一對(duì)key,value是一個(gè)元組
range(起始,結(jié)束,步長(zhǎng))
取頭不取尾