Python itertools.islice() function can allow us to get a part of an iterable object. In this tutorial, we will use some examples to show you how to do.
Syntax
itertools.islice() is defined as:
itertools.islice(iterable, stop) itertools.islice(iterable, start, stop[, step])
It will return selected elements from the iterable. It will return a itertools.islice object.
We should notice:
- start = 0 if start is None.
- start = 0 if start < 0
How to use itertools.islice()?
Here is a simple example:
# islice('ABCDEFG', 2) --> A B
# islice('ABCDEFG', 2, 4) --> C D
# islice('ABCDEFG', 2, None) --> C D E F G
# islice('ABCDEFG', 0, None, 2) --> A C E G
We should notice, we can not set value for start or stop parameter.
For example:
from itertools import islice
s = 'ABCDEFG'
y = islice(s, start = 1, stop = 3)
print(y)
for x in y:
print(x)
Run this code, we will get an error: TypeError: islice() does not take keyword arguments
The correct way is:
y = islice(s, 1, 3)
print(y)
for x in y:
print(x)
Then we can find:
y is <itertools.islice object at 0x000001C5131F6D68>
and x is: B C