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Regex to validate date format dd/mm/yyyy
I need to validate a date string for the format dd/mm/yyyy with a regular expresssion.
20 Answers
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Mapping two integers to one, in a unique and deterministic way
Imagine two positive integers A and B. I want to combine these two into a single integer C.
18 Answers
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List of lists changes reflected across sublists unexpectedly
I needed to create a list of lists in Python, so I typed the following:
14 Answers
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Pandas groupby: How to get a union of strings
I have a dataframe like this:
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Drop rows with all zeros in pandas data frame
I can use pandas dropna() functionality to remove rows with some or all columns set as NA 's. Is there an equivalent function for dropping rows with all columns having value 0?
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Shortest distance between a point and a line segment
I need a basic function to find the shortest distance between a point and a line segment. Feel free to write the solution in any language you want; I can translate it into what I'm using (Javascript).
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Simple C example of doing an HTTP POST and consuming the response
I would like to create a very simple C application that does an HTTP post. It will take a few parameters, and use these to construct a URL. I'd just like to do a simple HTTP POST and get the response without the use of curl (the libraries are not and will not be installed on the machine this needs...
Multiple linear regression in Python
I can't seem to find any python libraries that do multiple regression. The only things I find only do simple regression. I need to regress my dependent variable (y) against several independent variables (x1, x2, x3, etc.).
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How to select rows with one or more nulls from a pandas DataFrame without listing columns explicitly
I have a dataframe with ~300K rows and ~40 columns.
I want to find out if any rows contain null values - and put these 'null'-rows into a separate dataframe so that I could explore them easily.
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How can I check if a string represents an int, without using try/except?
Is there any way to tell whether a string represents an integer (e.g., '3' , '-17' but not '3.14' or 'asfasfas' ) Without using a try/except mechanism?
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