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+--- Thread: number plus suffix (/thread-18831.html)
number plus suffix - Skaperen - Jun-03-2019
i want to convert a number that has a suffix following the digits. i think i will need to split it at the point where the digits end and the suffix begins. the tool to convert ints in C (strtol) can also yield a pointer to where the digits end. int() in Python does not do that and will even fail the conversion if any non-digits follow the digits. i want to convert strings like '5m' and extract the suffix to work with that.
'm' can mean minutes, and with a map having 'm':60 multiply the 5 to get 300. i'd like to also support other bases like int(digits,0)RE: number plus suffix - Gribouillis - Jun-03-2019
It seems that regular expressions are the appropriate tool
>>> import re
>>> re.match(r"^(\d+)(.*)$", "5m").groups()
('5', 'm')
RE: number plus suffix - perfringo - Jun-03-2019
itertools module comes in mind, specifically dropwhile and groupby
>>> from itertools import dropwhile >>> t = '5hours' >>> ''.join([char for char in dropwhile(lambda char: char.isdigit(), t)]) # add .strip() if there is space between numbers and letters hours >>> from itertools import groupby >>> t = '5hours' >>> [''.join(group) for status, group in groupby(t, lambda char: char.isalpha()) if status == True][0] hours
RE: number plus suffix - Skaperen - Jun-03-2019
i'd like to solve the general case, like if my function was processing digits one at a time and stopping when something is not a valid digit which might need to be determined in context, such as convert a number and return a 2-tuple with the value and what cannot be processed. but the number's base may not be known in advance.
RE: number plus suffix - Gribouillis - Jun-05-2019
I posted a snippet for a python version of strtol here.
RE: number plus suffix - Skaperen - Jun-05-2019
i was hoping there was a way to avoid parsing individual digits in Python, but it looks to be the only way to do it for this need. thanks for the link.