python-字符串操作

python字符串操作

count()统计字符在字符串中出现的次数

name = "zhangSan"
num = name.count('S')
print("{0}".format(num))
# 打印结果:1

name = "zhangSan"
num = name.count('S', 0, 3) #从0，1，2索引里找
print("{0}".format(num))
# 打印结果:0

encode()字符串编码

name = "zhangsan"
name = name.encode('gbk')
print("{0}".format(name))
# 打印结果:b'zhangsan'

startswith()判断字符串以某个字符串开头，返回boolean类型

name = "zhangsan"
isTrue = name.startswith("zh")
print(isTrue)
# 打印结果:True

endswith()判断字符串以某个字符串结尾，返回boolean类型

name = "zhangsan"
isTrue = name.endswith("san")
print(isTrue)
# 打印结果:True

find()在字符串中查找指定字符串，找不到时返回-1

name = "zhangsan"
isIn = name.find("an")
print(isIn)
# 打印结果:2
# 返回字符串开始的下标

format()格式化输出字符串

name = "{} {} zhangsan" #"{} {}"是占位符，用下边format()里边的参数填充
name = name.format('I', 'am')
print(name)
# 打印结果:I am zhangsan

index()在字符串中查找指定的字符串,找不到时直接报错

name = "zhangsan"
isIn = name.index('h')
print(isIn)
# 打印结果:1

find()找不到时返回-1  index()找不到时，直接报错

join()字符串连接

name = "zhangsan"
name = '*'.join(name)
print(name)
# 打印结果:z*h*a*n*g*s*a*n

isalnum()判断字符串是否包含字母数字字符

name = "zhangsan1"
isTrue = name.isalnum()
print(isTrue)
# 打印结果:True

name = "zhangsan1*"
isTrue = name.isalnum()
print(isTrue)
# 打印结果:False

isalpha()判断是否只包含字母

name = "zhangsan"
isTrue = name.isalpha()
print(isTrue)
# 打印结果:True

name = "zhangsan1"
isTrue = name.isalpha()
print(isTrue)
# 打印结果:False

isdigit()判断字符串只由数字构成

name = "1234"
isTrue = name.isdigit()
print(isTrue)
# 打印结果:True

name = "zhangsan1234"
isTrue = name.isdigit()
print(isTrue)
# 打印结果:False

isspace()判断字符串是否是空格

name = " "
isTrue = name.isspace()
print(isTrue)
# 打印结果:True

name = "zhang san"
isTrue = name.isspase()
print(isTrue)
# 打印结果:False

isupper()判断字符串是否全是大写字符

name = "ZHANGSAN"
isTrue = name.isupper()
print(isTrue)
# 打印结果:True

lower()将所有的大写字符转为小写字符

name = "ZHANGSAN"
name = name.lower()
print(name)
# 打印结果:zhangsan

lstrip()去除字符串左边的空格

name = "   zhangsan  "
name = name.lstrip()
print(name)
# 打印结果:zhangsan  

rstrip()去除字符串右边的空格

name = "   zhangsan  "
name = name.rstrip()
print(name)
# 打印结果:   zhangsan

去除字符串2边的空格

name = "   zhangsan   "
name = name.strip()
print(name)
# 打印结果:zhangsan

replace()字符串替换

name = "zhangsan"
name = name.replace("zhang", "li")
print(name)
# 打印结果:lisan

split()字符串分割，默认是空格

name = "zhang san"
name = name.split()
print(name)
# 打印结果:['zhang', 'san']

add()在字符串后边添加字符串

name = "zhang"
name = name.__add__("san")
print(name)
# 打印结果:zhangsan

contains()判断指定字符串是否包含在字符串中

name = "zhangsan"
isTrue = name.__contains__("san")
print(isTrue)
# 打印结果:True

eq（）判断字符串是否相等

name = "zhangsan"
name1 = "zhangsan"
isEq = name.__eq__(name1)
print(isEq)
# 打印结果:True