27 lines
635 B
Markdown
27 lines
635 B
Markdown
---
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title: Reverse compose functions
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tags: function
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expertise: advanced
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firstSeen: 2020-01-02T15:51:26+02:00
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lastUpdated: 2020-11-02T19:27:07+02:00
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---
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Performs left-to-right function composition.
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- Use `functools.reduce()` to perform left-to-right function composition.
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- The first (leftmost) function can accept one or more arguments; the remaining functions must be unary.
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```py
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from functools import reduce
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def compose_right(*fns):
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return reduce(lambda f, g: lambda *args: g(f(*args)), fns)
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```
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```py
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add = lambda x, y: x + y
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square = lambda x: x * x
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add_and_square = compose_right(add, square)
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add_and_square(1, 2) # 9
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```
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