Python Generators: Difference between revisions
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=Overview= | =Overview= | ||
A generator is a way to construct a new [[Python_Iterators#Overview|iterable]] object. Whereas normal functions execute and return a single result at a time, generators can return a sequence of multiple values by pausing and resuming execution each time the generator is used. To create a generator, use the <code>[[Python_Language#yield|yield]]</code> keyword instead of <code>return</code> in a function. | A generator is a way to construct a new [[Python_Iterators#Overview|iterable]] object. Whereas normal functions execute and return a single result at a time, generators can return a sequence of multiple values by pausing and resuming execution each time the generator is used. To create a generator, use the <code>[[Python_Language#yield|yield]]</code> keyword instead of <code>return</code> in a function. | ||
<syntaxhighlight lang='py'> | |||
def squares(n=10): | |||
for i in range(1, n+1): | |||
yield i ** 2 | |||
</syntaxhighlight> | |||
When the generator is called no code is immediately executed: | |||
<syntaxhighlight lang='py'> | |||
gen = squares() | |||
</syntaxhighlight> | |||
It is not until you request elements from the generator that it begins executing code: | |||
<syntaxhighlight lang='py'> | |||
for x in gen: | |||
print(x) | |||
</syntaxhighlight> | |||
=Use Cases= | =Use Cases= | ||
Create a [[Python_Language_List#Pass_a_Generator_Expression|list with a generator]]. | Create a [[Python_Language_List#Pass_a_Generator_Expression|list with a generator]]. | ||
Revision as of 19:05, 17 May 2024
Internal
TODO
- PROCESS IPy Generators Page 101.
- PROCESS PyOOP "Generator expressions"
- PROCESS PyOOP "Generators" + "Yield items from another iterable"
Overview
A generator is a way to construct a new iterable object. Whereas normal functions execute and return a single result at a time, generators can return a sequence of multiple values by pausing and resuming execution each time the generator is used. To create a generator, use the yield keyword instead of return in a function.
def squares(n=10):
for i in range(1, n+1):
yield i ** 2
When the generator is called no code is immediately executed:
gen = squares()
It is not until you request elements from the generator that it begins executing code:
for x in gen:
print(x)
Use Cases
Create a list with a generator.