Generate list of numbers and their negative counterparts
Python 2, 33 bytes



def f(a,b):print-a,a;a&lt;b&lt;f(a+1,b)


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A recursive function that prints in a two-column format. Based on ideas from Surculose Sputum.

In Python 3, we'd need 2 more bytes for print() needing parens.



Python 2, 37 bytes



lambda a,b:range(a,b+1)+range(-b,1-a)


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Unfortunately for this challenge, Python's ranges are exclusive, so we have to add 1 to both upper endpoints.