Python slice()
Python slice() builtin function returns an object of type slice. This slice object can be used to slice a Python sequence such as string, tuple, list, etc.
In this tutorial, we will learn about the syntax of Python slice() function, and learn how to use this function with the help of examples.
Syntax
The syntax of slice() function with stop
parameter is
slice(stop)
where
Parameter | Required/ Optional | Description |
---|---|---|
stop | Required | An integer. The index up until which the slice object contains the indices. |
The syntax of slice() function with start
, stop
and an optional step
parameter is
slice(start, stop[, step])
where
Parameter | Required/ Optional | Description |
---|---|---|
value | Required | An integer. The staring index from which the slice object contains the indices. |
stop | Required | An integer. The index up until which the slice object contains the indices. |
step | Optional | An integer. The step value is the difference between any two adjacent indices. The default step in a slice object is 1. |
Returns
The function returns an object of type slice.
Examples
1. slice(stop)
In this example, we call slice() function and give a value, say 4
, for stop parameter. The function returns a slice object. Let us print that slice object.
Python Program
stop = 3
slice_object = slice(stop)
print(slice_object)
Output
slice(None, 3, None)
Now, let us use this slice object to slice a sequence, say a string.
Python Program
stop = 3
slice_object = slice(stop)
x = 'abcdefgh'
print(x[slice_object])
Output
abc
Explanation
'a b c d e f g h' :input string
0 1 2 3 4 5 6 7 :indices
|stop=3
0 1 2 :indices in slice object
a b c :resulting string of x[slice_object]
2. slice(start, stop)
In this example, we call slice() function and get a slice object with start=2 and stop=5. We will use this slice object, to slice a string.
Python Program
start = 2
stop = 5
slice_object = slice(start, stop)
x = 'abcdefgh'
print(x[slice_object])
Output
cde
Explanation
'a b c d e f g h' :input string
0 1 2 3 4 5 6 7 :indices
start=2| |stop=5
2 3 4 :indices in slice object
c d e :resulting string of x[slice_object]
3. slice(start, stop, step)
In this example, we call slice() function and get a slice object with start=2 and stop=9 and step=2. We will use this slice object, to slice a string.
Python Program
start = 2
stop = 9
step = 2
slice_object = slice(start, stop, step)
x = 'abcdefghijklm'
print(x[slice_object])
Output
cegi
Explanation
'a b c d e f g h i j k l m' :input string
0 1 2 3 4 5 6 7 8 9 10 11 12 :indices
start=2| |stop=9
2 4 6 8 :indices in slice object with step=2
c e g i :resulting string of x[slice_object]
Conclusion
In this Python Tutorial, we have learnt the syntax of Python slice() builtin function, and also learned how to use this function, with the help of Python example programs.