Python 005:循環語句
循環語句
1.while循環:用於功能循環;
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count = 0
while count < 5:
print (count, " 小於 5")
count = count + 1
else:
print (count, " 大於或等於 5")
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2.for循環:遍歷循環,用於迭代出list或tuple中的元素;
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sites = ["Baidu", "Google","Runoob","Taobao"]
for site in sites:
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m = [i**2 for i in range(5)]
# 運行結果:[0,1,4,9,16]
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for i in range(0,10):
if i<3:
print(loop,i)
else:
continue
print(mm)
# 運行結果:
loop 0
mm
loop 1
mm
loop 2
mm
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其他
1.range函數:遍歷序列函數[m,n);
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a = [Google, Baidu, Runoob, Taobao, QQ]
for i in range(len(a)):
print(i, a[i])
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r =range(0,8,1) # 0是起始位置,8是末位位置(注意不包含),1是間隔數量;
#運行結果:[0,1,2,3,4,5,6,7] # 返回的是列表;
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break、continue、pass
break:該條件下,不執行後面的循環;
continue:特定條件下不執行部分程序;
pass:特定條件下才執行部分程序;
2.break語句:跳出整個循環;
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a = [Google, Baidu, Runoob, Taobao, QQ]
for letter in Runoob:
if letter == o:
break
print (當前字母為 :, letter)
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3.continue語句:跳出本次循環,進入下一次循環;# 即停止後面的循環,開始下一次循環
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a = [Google, Baidu, Runoob, Taobao, QQ]
for letter in Runoob:
if letter == o:
continue
print (當前字母 :, letter)
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2.pass語句:佔位符作用,只有符合要求的情況才會執行後面的內容;
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a = [Google, Baidu, Runoob, Taobao, QQ]
for i in a:
if i == o:
pass
print(pass是佔位符作用)
print(i)
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