Python looper - itertools

I. Introduction

Python's built-in modules itertoolsprovide very useful functional methods for manipulating iterables, such as infinite loops in 1 and 2, and Cartesian product loops that combine two lists.

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2. Examples

1. Repeat the elements in the list cycle-cycle

The following code will repeat 1,2,3 for infinite printing:

from itertools import *

for i in cycle([1,2,3]):
    print(i)

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output result

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1
2
3
1
2
...

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2. Accumulation loop -count

The following code will start at 10 and print infinitely every time it increases by 1.5:

from itertools import *

for i in count(10,1.5):
    print(i)

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output result

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10
11.5
13.0
...

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3. Repeat loop -repeat

The following code prints 10 infinitely:

from itertools import *

for i in repeat(10):
    print(i)

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output result

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10
10
10
...

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You can also specify the number of loops, such as specifying 5 loops:

from itertools import *

for i in repeat(10,5):
    print(i)

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3. Summary

In addition to the above examples, there are many methods for us to use, you can directly visit the official documentation: https://docs.python.org/zh-cn/3/library/itertools.html for learning:

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I recently read the official Python documentation: https://docs.python.org/zh-cn/3/contents.html and found a lot of skills that I didn’t know before. You can also go to the official documentation to supplement it, and there will be many reward.

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Note: Remember to select the documentation for the corresponding version of python in your environment:

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