str.isdigit() vs str.isnumeric()

str.isdigit() vs str.isnumeric() - Printable Version

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str.isdigit() vs str.isnumeric() - Skaperen - Jun-13-2019

can anyone summarize the differences between str.isdigit() and str.isnumeric() and maybe also str.isdecimal()? i have been checking numbers with try/expect around int() or float() in part because if i have success, i have the converted value.

RE: str.isdigit() vs str.isnumeric() - perfringo - Jun-13-2019

I agree that from documentation of str.isidigit(), str.isnumeric(), str.isdecimal() is hard to comprehend differences between these string methods.

Subtle differences include:

- str.isdigit() returns True if strings containing only the digits 0-9
- str.isnumeric() returns True if string contains only numeric characters (including 0-9 but also likes Japanese kanji one '一')
- str.isdecimal() returns True if string contains only decimal numbers (1² is not decimal number, but it's str.isdigit() and str.isnumeric())

>>> digits = '123'
>>> numerics = '一二三'   # '123'in Kanji
>>> decimals = '1²'
>>> digits.isdigit()                                                       
True
>>> numerics.isdigit()                                                     
False
>>> decimals.isdigit()                                                     
True
>>> digits.isnumeric()                                                     
True
>>> numerics.isnumeric()                                                   
True
>>> decimals.isnumeric()                                                   
True
>>> digits.isdecimal()                                                     
True
>>> numerics.isdecimal()                                                   
False
>>> decimals.isdecimal()                                                   
False

RE: str.isdigit() vs str.isnumeric() - Skaperen - Jun-13-2019

now i am wondering what was the intended purpose of these 3 different bethods.

RE: str.isdigit() vs str.isnumeric() - perfringo - Jun-13-2019

I think that digging in mail.python.org may give answer to that.

To add some confusion, str.isdecimal() returns True for decimal numbers in some(?) character systems.

>>> kanji = '一'               # Kanji 1                                            
>>> thai = '๑'                 # Thai digit 1                                            
>>> kanji.isdecimal()                                                      
False
>>> thai.isdecimal()                                                       
True
>>> int(thai)
1
>>> int(kanji)
/.../
ValueError: invalid literal for int() with base 10: '一'

RE: str.isdigit() vs str.isnumeric() - Skaperen - Jun-14-2019

and i am curious if any of them is an exact match to what int(str,0) accepts.