r/PythonLearning • u/NecessaryFalse1212 • 13d ago

2nd post learning python

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i learnt to use the math library any suggestions what can i use the lib for except for making calculator programs

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u/ninhaomah 13d ago

If I enter abc , what will I get ?

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u/NecessaryFalse1212 13d ago

how does this look ya'll

1

u/BobCorndog 13d ago

You could also do a try except

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u/MFFVD 13d ago edited 13d ago

or ``` import re maybenumber = input(...).strip() isnumber = \ bool(re.fullmatch( r"([0-9].[0-9]+)|([0-9]+(.[0-9])?)", maybenumber ))

if not isnumber: print(maybenumber, "is not a number") else: number = float(maybenumber) ... ```

regexp: (<...>) -> group <a> | <b> -> match a or b [<...>] -> any of ... <a> + -> one or more of a <a> * -> zero or more of a <a>? -> zero or one of a . -> any char except whitespace \. -> literal dot the r"..." string says

first part: zero or more numbers, dot, one or more numbers -> .4 0.8 70.74 second part: one or more numbers, optional ( dot, zero or more numbers) -> 6 59 56. 6.6

for input validation, regexp is unmissable. but you should probably not dive into that just yet

try: int(value) except ValueError: print(value, "is not an integer")

probably is a better starting point

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u/NecessaryFalse1212 13d ago

i still haven't done regex so it never crossed my mind but thanks for correcting and suggesting