strin 字符串的內置函數
阿新 • • 發佈:2018-01-27
字符 輸出結果 子串 split 程序 bstr 所有 style 統計
count("x")統計字符串的元素的個數 a = "hello kitty" print (a.count("t"))#統計t出現的個數 輸出結果: 2
endswith("x")判斷以某個字符結尾 a = "python" print (a.endswith("n")) print (a.endswith("on")) print (a.endswith("hon")) print (a.endswith("nn")) 輸出結果: True True True False
startswith("x")判斷以某個字符開頭 a = "python" print (a.startswith("p")) print (a.startswith("py")) print (a.startswith("pyt")) print (a.startswith("pp")) 輸出結果: True True True False
capitalize()把字符串首寫字母大寫 a = "python" print (a.capitalize()) 輸出結果: Python
upper()將字符串裏的小寫變成大寫 a = "python" print (a.upper()) 輸出結果: PYTHON
lower()把字符串大寫變成小寫 a = "PYTHON" print (a.lower()) 輸出結果: python
swapcase()把字符串裏的大小寫反轉 a = "PyThoN" print (a.swapcase()) 輸出結果: pYtHOn
isupper()判斷字符串是否大寫 a = "python" a1 = "PYTHON" print (a.isupper()) print (a1.isupper()) 輸出結果: False True
islower()判斷字符串是否小寫 a = "python" a1 = "PYTHON" print (a.islower()) print (a1.islower()) 輸出結果: True False
isalnum()-判斷字符串是否是字母或者數字 a= "python" a1 = "123" a2 = "python123" a3 = "中國" a4 = "#$###" print (a.isalnum()) print (a1.isalnum()) print (a2.isalnum()) print (a3.isalnum()) print (a4.isalnum()) 輸出結果: True True True True False
istitle()判斷首寫字母是否為大寫 a = "python" a1 = "Python" a2 = "PYTHON" print (a.istitle()) print (a1.istitle()) print (a2.istitle()) 輸出結果: False True Fals
strip()把字符串左右空格去掉 a = " python " print (a.strip()) 輸出結果: python #已經將左右空格去掉了,這樣看不出來 ---------------------- strip()也會把\n換行去掉 a = "python\n" a1 = "hello" print (a.strip()) #strip()把換行去掉了 print (a1) 輸出結果: python hello ---------------------- a = "python\n" a1 = "hello" print (a)#不使用strip(),將會換行 print (a1) 輸出結果: python hello
lstrip()去掉字符串左空格 a = " python " print (a.strip()) 輸出結果: python #最後面這有空格,這樣看不出來
rstrip()去掉字符串右空格 a = " python " print (a.rstrip()) 輸出結果: python #已經將右邊空格去掉了,這看不出來
replace(old,new) 把字符串的內容替換掉 a = "my tang" print (a.replace("tang", "guo")) 輸出結果: my guo
split(分割符,分割次數)對字符串進行各種分割 a = "my \ntang guo\nli" print (a.split())#不指定以什麽分割的情況下,會默認所有的空格,換行,制表符分割 輸出結果: [‘my‘, ‘tang‘, ‘guo‘, ‘li‘] ------------------------------------- a = "my tang guo" print (a.split(" ")) #以空格進行分割 輸出結果: [‘my‘, ‘tang‘, ‘guo‘] -------------------------------------- a = "my tang guo li" print (a.split(" ",2))#以空格進行分割2次 輸出結果: [‘my‘, ‘tang‘, ‘guo li‘] --------------------------------------- a = "my tang guo li" print (a.split("a"))#以 a進行分割,a會被切掉 輸出結果: [‘my t‘, ‘ng guo li‘] -------------------------------------- 可以指定多個字符進行分割 a = "my tang guo li" print ((a.split("an"))#以 an進行分割,an會被切掉 ["my t" ,"g guo li"] ----------------------------------------
isdigit()判斷字符串是否為整型 a = "python" a1 = "123" print (a.isdigit()) print (a1.isdigit()) 輸出結果: True False
rfind("x")查找元素所在的索引位置,從右向左開始找,找到的第一個元素位置 a = "htp" a1 = "http" print (a.rfind("t")) print (a1.rfind("t")) 輸出結果: 1 2 ----------------------------------------------------------------- find("x")從左向右開始找元素,找到的第一個位置,並返回索引位置 a = "htp" a1 = "http" print (a.find("t")) print (a1.find("t")) 輸出結果: 1 1
index("x")從左向右開始找元素的位置, a = "ppython" print (a.index("p")) #有多個相同元素時,返回的是第一個找到的索素值 輸出結果: 0
find 與 index看上去功能一樣,其實是有區別的
a = "python"
print (a.index(x))
index 在沒有找到子串的時候會報錯(ValueError: substring not found),影響程序執行。
print (a.find("x"))
find 在沒有找到子串時,不會報錯,而是會返回-1所以不會影響執行。
strin 字符串的內置函數