大小写转换

print("name is Alex".capitalize())  # 转为首字母大写 ->Name is alex
print("name is Alex".title())  # 转为标题形式 ->Name Is Alex
print("Name".upper())   # 转大写 ->NAME
print("Name".lower())   # 转小写 ->name
print("Name".swapcase())  # 交换大小写 ->aLEX

字符串判断

print("name is Alex".startswith("name"))  # 以...开头 ->True
print("name is Alex".endswith("Alex"))  # 以...结尾 ->True
print("123abc".isalnum())  # 字母或数字 ->True
print("abc".isalpha())  # 字母 ->True
print("123".isdigit())  # 数字 ->True
print("123".isnumeric())  # 数字 ->True
print("abc".isidentifier())  # 判断是否为合法变量名 ->True
print(" ".isspace())  # 空格 ->True
print("My Name Is Tom".istitle())  # 标题 ->True
print("My Name Is Tom".isprintable())  # 可打印 tty file, drive file ->True
print("MY".isupper())  # 大写 ->True
print("my".islower())  # 小写 ->True

输出显示

print(",".join(["1", "2", "3"]))  # 连接
#  ->1,2,3
print("name is Alex".split())  # 拆分为列表，默认拆分符为空格
#  ->['name', 'is', 'Alex']
print("name\n is\r\n Alex".splitlines())  # 拆分为列表，默认拆分符为回车
#  ->['name', ' is', ' Alex']
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 Alex".expandtabs(tabsize=20))  # 设置'\t'宽度
# ->name is              Alex
print("I am from {city},and {year} years old".format(city="Wuhan", year=23))  # 格式化
# ->I am from Wuhan,and 23 years old
print("I am from {city},and {year} years old".format_map({"city": "Wuhan", "year": 23}))  # 字典参数格式化
# ->I am from Wuhan,and 23 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

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 Tom".replace("n", "N"))  # 替换 ->Name is Tom
print("name is Alix".count("i"))  # 字符计数 ->2
print("name is Alex".find("e"))  # 查找，返回下标，没有则返回-1 ->3
print("name is Alex".rfind("e"))  # 右边开始查找 ->10
print("name is Alex".index("e"))  # 返回索引，不存在则报错 ->3
print("name is Alex".rindex("e"))  # 右边开始查找 ->10