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Anonymous variables and subs and lambdas
Functions, Modules and Packages example from a Well House Consultants training course
More on Functions, Modules and Packages [link]
Source code: mutton Module: Y105
"""Why do you name variables? So that you can use them again
later. But if you don't want to use them more than once, why bother with a name at all? Most programming languages create temporary or anonymous variables within a single line, and if you've programmed almost anything, you'll have used them without realising it. In Python, everything is an object - and that includes functions. And so, just as you're allowed anonymous scalars and lists, you're allowed anonymous functions. They're defined using the lambda keyword .... """ # Define a named function def cricket(input): return input//11 # Define an anonymous function (but then save it # into a named variable) rugby = lambda x: (x-7)//15 # Define a list of functions - some of which are # aliases for the functions which have already been # defined, and others are new and unnamed games = (cricket, rugby, lambda input:input//2, lambda x:x) people = [150,175,210,50] # Use a named function in a mapping teams = map(cricket, people) print("cricket - ",list(teams)) # Use a named function in a mapping teams = map(rugby, people) print("rugby - ",list(teams)) # Use an anonymous function (lambda) in a mapping teams = map(lambda x: x//7, people) print( "water polo - ",list(teams)) # Loop through and call a list of functions for k in range(0,len(games)): teams = map(games[k], people) print( "seasonal - ",list(teams)) """ Here's what that looks like when you run it: WomanWithCat:y105 grahamellis$ python2 mutton ('cricket - ', [13, 15, 19, 4]) ('rugby - ', [9, 11, 13, 2]) ('water polo - ', [21, 25, 30, 7]) ('seasonal - ', [13, 15, 19, 4]) ('seasonal - ', [9, 11, 13, 2]) ('seasonal - ', [75, 87, 105, 25]) ('seasonal - ', [150, 175, 210, 50]) WomanWithCat:y105 grahamellis$ python3 mutton cricket - [13, 15, 19, 4] rugby - [9, 11, 13, 2] water polo - [21, 25, 30, 7] seasonal - [13, 15, 19, 4] seasonal - [9, 11, 13, 2] seasonal - [75, 87, 105, 25] seasonal - [150, 175, 210, 50] WomanWithCat:y105 grahamellis$ """ Learn about this subject
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