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
# 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,
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]
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* Learning to program in Python
* Python Programming
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