Python学习之路-string字符串的常用方法

大小写转换

__author__ = "KuanKuan"
print("name is JankinYu".capitalize())#转为首字母大写
print("name is JankinYu".title())#转为标题形式   Name Is Jankinyu
print("NAMW".lower())#转换为小写
print("name".upper())#转换为大写
print("Name".swapcase())#大写变小写小写变大写
"""
输出结果：
Name is jankinyu
Name Is Jankinyu
namw
NAME
nAME
"""

字符串判断

__author__ = "KuanKuan"
print("name is JankinYu".startswith("name")) # 以...开头  如果正确则为True
print("name is JankinYu".endswith("JankinYu"))#以...结尾  如果正确则为True
print("asd".isalpha())#如果是字母则为True
print("123".isdigit())#如果是数字则为True
print("asd123".isalnum())#如果是数字或者字母则为True
print("jjk".isidentifier())#判断是否为合法变量名合法为True
print(" ".isspace())  # 空格 -->True
print("My Name Is Jankinyu".istitle())  # 标题 -->True
print("My Name Is Jankinyu".isprintable())  # 可打印 tty file, drive file -->True
print("A".isupper())  # 大写 -->True
print("a".islower())  # 小写 -->True

输出显示

__author__ = "KuanKuan"
print(",".join(["1", "2", "3"]))  # 连接
#  ->1,2,3
print("name is JankinYu".split())  # 拆分为列表，默认拆分符为空格
#  ->['name', 'is', 'JankinYu']
print("name\n is\r\n  JankinYu".splitlines())  # 拆分为列表，默认拆分符为回车
#  ->['name', ' is', 'JankinYu']
print("name".center(50, "-"))  # 内容居中，两侧填充
# ->-----------------------name-----------------------
print("name".ljust(50, "*"))  # 内容靠左，以*填充
# ->name**********************************************
print("name".rjust(50, "-"))  # 内容靠右，以-填充
# ->----------------------------------------------name
print("name".zfill(50))  # 内容靠右，以0填充
# ->0000000000000000000000000000000000000000000000name
print("name is\t  JankinYu".expandtabs(tabsize=18))  # 设置'\t'宽度
# ->name is               JankinYu
print("I am from {city},and {year} years old".format(city="kuankuan", year=18))  # 格式化
# ->I am from Wuhan,and 18 years old
print("I am from {city},and {year} years old".format_map({"city": "kuankuan", "year": 18}))  # 字典参数格式化
# ->I am from Wuhan,and 18 years old
print("\nname".lstrip())  # 去除左侧回车和空格 ->name
print("name\n".rstrip())  # 去除右侧回车和空格 ->name
print("    name\n".strip())  # 去除两侧回车和空格 ->name
print("~~~~~~~~~~~~~~~~~~~~")

查找替换

__author__ = "KuanKuan"
p = str.maketrans("abc", "123")  # 创造翻译字典
print(type(p))  # --><class 'dict'>
print("abc".translate(p))  # 翻译，参数：dict -->123
print("name is JankinYu".replace("n", "N"))  # 替换 -->Name is JankinYu
print("name is JankinYu".count("i"))  # 字符计数 -->2
print("name is JankinYu".find("n"))  # 查找，返回下标，没有则返回-1 -->2
print("name is JankinYu".rfind("n"))  # 右边开始查找 -->13
print("name is JankinYu".index("n"))  # 返回索引，不存在则报错 -->0
print("name is JankinYu".rindex("n"))  # 右边开始查找 -->13
"""
输出结果：
<class 'dict'>
123
Name is JaNkiNYu
2
0
13
0
13
"""