Difference between List comprehension and Lambda in Python
List comprehension is an elegant way to define and create a list in Python. We can create lists just like mathematical statements and in one line only. The syntax of list comprehension is easier to grasp.
A list comprehension generally consists of these parts :
- Output expression,
- Input sequence,
- A variable representing a member of the input sequence and
- An optional predicate part.
Syntax of list comprehension
List = [expression(i) for i in another_list if filter(i)]
[1, 9, 25, 49, 81]
In the above example,
- x ** 2 is the expression.
- range (1, 11) is an input sequence or another list.
- x is the variable.
- if x % 2 == 1 is predicate part.
What is lambda?
In Python, an anonymous function means that a function is without a name. As we already know the def keyword is used to define the normal functions and the lambda keyword is used to create anonymous functions. It has the following syntax:
Syntax of lambda
lambda arguments : expression
[1, 4, 9, 16]
The difference between Lambda and List Comprehension
List Comprehension is used to create lists, Lambda is function that can process like other functions and thus return values or lists.
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9] [0, 2, 4, 6, 8, 10, 12, 14, 16, 18] [0, 2, 4, 6, 8, 10, 12, 14, 16, 18]
Graphical representation of list comprehension vs lambda + filter
As we can see from the graph that overall list comprehension is much faster than the filter function. The filter is faster for a small list only.