python字串操作

標籤：python字串   python   python基礎   

1、字串首字母大寫

>>> name = "xiaoming"

>>> print(name.capitalize())      //capitalize方法可以使字串首字母大寫

Xiaoming

2、統計字串中字元的個數

>>> name = "xiaoming"

>>> print(name.count("i"))

2

3、重複列印某個字元

>>> print(name.center(20,"-"))   //總共有20個字元，把"xiaoming"放在中間

------xiaoming------

4、判斷字串以什麼結尾

>>> name = "xiaoming"

>>> print(name.endswith("ng"))

True

5、根據字元找索引位置

>>> name = "My name is Xiaoming"

>>> print(name.find("is"))          //find只列印尋找到的字元的開頭字母的位置

8

>>> print(name[name.find("is"):])     //字串也支援切片

is Xiaoming

6、字串格式化輸出

>>> name = "My name is {name} and I am {year} years old."

>>> print(name.format(name="Xiaoming",year=20))             //format格式化輸出

My name is Xiaoming and I am 20 years old.

>>> print(name.format_map( {"name":"Xiaoming","year":25} ))     //format_map可以以字典的格式進行傳輸

My name is Xiaoming and I am 25 years old.

7、判斷字串是不是純英文字元組成

>>> name = "abc"

>>> print(name.isalpha())

True

>>> name = "ab12"

>>> print(name.isalpha())

False

8、判斷數字是不是整數

>>> print("aa".isdigit())

False

>>> print("11".isdigit())

True

>>> print("11.2".isdigit())

False

9、判斷字串是不是小寫

>>> name = "abc"

>>> print(name.islower())

True

>>> name = "My"

>>> print(name.islower())

False

10、判斷字串中的字元開頭是不是大寫字母

>>> name = "my name"

>>> print(name.istitle())

False

>>> name = "My Name"

>>> print(name.istitle())

True

11、判斷字串是不是全是大寫字母

>>> name = "MY NAME"

>>> print(name.isupper())

True

12、join的簡單使用

>>> print("".join(["1","2","3"]))

123

>>> print("+".join(["1","2","3"]))

1+2+3

13、ljust()和rjust()的使用

>>> name

'MY NAME'

>>> print(name.ljust(20,"*"))    //注意：是整個字串共長20，"MY NAME"共長7，所以"*"只有13個

MY NAME*************

>>> print(name.rjust(20,"*"))

*************MY NAME

14、字串的大小寫轉換

>>> name

'MY NAME'

>>> print(name.lower())      //lower是把大寫變成小寫

my name

>>> print(name.upper())      //upper是把小寫轉換為大寫

MY NAME

15、去除字串兩頭的斷行符號或者空格

>>> print("\nMy name")

My name

>>> print("\nMy name".lstrip())     //lstrip為去除字串左邊的空格或斷行符號

My name

>>> print("My name\n")

My name

>>> print("My name\n".rstrip())    //rstrip為去除字串右邊的空格或斷行符號

My name

>>> print("\nMy name\n".strip())   //strip為去除兩頭的空格或斷行符號

My name

16、字元的替換

>>> print("abca".replace("a","L"))        //預設為全部替換

LbcL

>>> print("abca".replace("a","L",1))       //可以指定

Lbca

17、字串分割成列表

>>> print("My name is Xiaoming".split())      //預設為空白格

['My', 'name', 'is', 'Xiaoming']

>>> print("My name is Xiaoming".split("i"))    //可以指定分隔字元

['My name ', 's X', 'aom', 'ng']

18、swapcase，把字串中的小寫轉大寫，大寫轉小寫

>>> print("My name is".swapcase())

mY NAME IS

python字串操作