python基础－字符串

 

 

字符串的各种方法

name = "adamanter Antonio Hello ALEX"

# 字符串首字母大写
print(name.capitalize())
#Adamanter antonio hello alex

# 字符串全部小写
print(name.casefold())
#adamanter antonio hello alex


print(name.find("e")) #找到返回字母下标，找到第一个就返回了
print(name.find("sdf",3))  # 找不到false return  -1


# 字符串的format格式方法，很重要，运用普遍
name0 ="my   name is {},my age is {} years old"
print(name0.format("alex",22))

name1 ="my name is {name},my age is {age} years old"
print(name1.format(name='alex',age=22))

name2 ="my name is {name},my age is {age} years old"
print(name2.format_map({'name':"alex",'age':23}))

# 字符串的％格式方法，很重要，运用普遍，用％必需用s,d等表示字符串还是数字类型，而format不需要
username="ada"
password="123456"
print("hello123 my  name is %s,my pwd is %s"%(username,password))
print("hello123 my  name is {},my pwd is {}".format(username,password))



str="hello123,hello123,alex ada"
print(str.center(50,"-"))  #不足50字符，两侧填充－
print(str.ljust(50,"-"))    #不足50字符，右侧填充－
print(str.rjust(50,"-"))    #不足50字符，左侧填充－
print(str.count("hello123")) #统计重复个数，列表也有这个方法



# 字符串拼接方法
seq=("a","b","c")
print("-".join(seq))
# a-b-c

# 按照逗号分割，指定分割2次
print(str.split(",",2));
# ['hello123', 'hello123', 'alex ada']

# 默认空格进行分割
print(str.split())

# 保持特殊字符原味，URL路由中用的很多
print(r"$#^&*")


# 字符串替换
str123 ="hello123 world"
new_str123 = str123.replace("world","python")
print(new_str123)
print(str123)
# hello123 python
# hello123 world
#生成了新字符串，原字符串没有改变，所以用新改变需要新变量


list=['alex','ada','adamander']
list.append("hello")
print(list)
# 原列表发生了改变