s.isdigit、s.isnumeric、s.isdecima 有什么区别?

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num = "1"  #unicode

num.isdigit()   # True

num.isdecimal() # True

num.isnumeric() # True

num = "1" # 全角

num.isdigit()   # True

num.isdecima搜索l() # True

num.isnumeric() # True

num = b"1" # byte

num.isdigit()   # True

num.isdecimal() # AttributeError 'bytes' object has no attribute 'isdecimal'

num.isnumeric() # AttributeError 'bytes' object has no attribute 'isnumeric'

num = "IV" # 罗马数字

num.isdigit()   # True

num.isdecimal() # False

num.isnumeric() # True

num = "四" # 汉字

num.isdigit()   # False

num.isdecimal() # False

num.isnumeric() # True

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isdigit()

True: Unicode数字，byte数字（单字节），全角数字（双字节），罗马数字

False: 汉字数字

Error: 无

isdecimal()

True: Unicode数字，，全角数字（双字节）

False: 罗马数字，汉字数字

Error: byte数字（单字节）

isnumeric()

True: Unicode数字，全角数字（双字节），罗马数字，汉字数字

False: 无

Error: byte数字（单字节）

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import unicodedata

unicodedata.digit("2")   # 2

unicodedata.decimal("2") # 2

unicodedata.numeric("2") # 2.0

unicodedata.digit("2")   # 2

unicodedata.decimal("2") # 2

unicodedata.numeric("2") # 2.0

unicodedata.digit(b"3")   # TypeError: must be str, not bytes

unicodedata.decimal(b"3") # TypeError: must be str, not bytes

unicodedata.numeric(b"3") # TypeError: must be str, not bytes

unicodedata.digit("Ⅷ")   # ValueError: not a digit

unicodedata.decimal("Ⅷ") # ValueError: not a decimal

unicodedata.numeric("Ⅷ") # 8.0

unicodedata.digit("四")   # ValueError: not a digit

unicodedata.decimal("四") # ValueError: not a decimal

unicodedata.numeric("四") # 4.0

#"〇","零","一","壱","二","弐","三","参","四","五","六","七","八","九","十","廿","卅","卌","百","千","万","万","亿"