Can you use else in list comprehension Python?

6 Answers. Note that this only works in Python 2.5 and later. Also note, that the else is necessary and cannot be ommited, because a resulting value is always required. The code within join(), is that list comprehension when there is no bracket?

How do you list comprehension with if else?

Every comprehension can be written as statements if you name the result. v = [A if q(i) else B for i in L if p(i)] becomes v = [] , for i in L: if p(i): v. append(A if q(i) else B) .

How do I make a list comprehension in Python?

Rewrite loops and map() calls as a list comprehension in Python. Choose between comprehensions, loops, and map() calls….You can use a for loop to create a list of elements in three steps:

  1. Instantiate an empty list.
  2. Loop over an iterable or range of elements.
  3. Append each element to the end of the list.

Can Elif be used in list comprehension?

While a list comprehension won’t take an elif statement, it will take multiple nested else statements.

Is list comprehension faster than for loop?

List comprehensions are often not only more readable but also faster than using “for loops.” They can simplify your code, but if you put too much logic inside, they will instead become harder to read and understand.

Can we use break in list comprehension?

It’s working as i want. But the problem is that to get the value from len([ j for j in filterlist if j in i ])>0 , it will need to loop all the item inside the filterlist. So even if it match the first item in filterlist, the loop will have to go through till the end.

What is the list comprehension equivalent for?

List comprehension is an elegant way to define and create lists in Python. These lists have often the qualities of sets, but are not necessarily sets. List comprehension is a complete substitute for the lambda function as well as the functions map(), filter() and reduce().

What is list comprehension write an example?

List comprehension offers a shorter syntax when you want to create a new list based on the values of an existing list. Example: Based on a list of fruits, you want a new list, containing only the fruits with the letter “a” in the name.

What is list comprehension give example?

One of the applications of list comprehension is to flatten a list comprising of multiple lists into a single list. Example: List Comprehension. matrix=[[1, 2, 3], [4, 5, 6], [7, 8, 9]] flatList=[num for row in matrix for num in row] print(flatList) [1, 2, 3, 4, 5, 6, 7, 8, 9]

How do you use Elif in list comprehension?

  1. # Basic syntax for if: desired_elements = [f(x) for x in iterable_object if condition]
  2. # Basic syntax for if else: desired_elements = [f(x) if condition else g(x) for x in iterable_object]
  3. # Basic syntax for if elif else:
  4. your_list = [1, 7, 13, 11, 23, 2, 17, 42, 8, 5]

Is list comprehension slow?

List comprehensions are faster than for loops to create lists. But, this is because we are creating a list by appending new elements to it at each iteration. This is slow.

What’s faster than a for loop?

Conclusions. List comprehensions are often not only more readable but also faster than using “for loops.” They can simplify your code, but if you put too much logic inside, they will instead become harder to read and understand.

Are there dictionary comprehensions in Python?

Comprehensions in Python provide us with a short and concise way to construct new sequences (such as lists, set, dictionary etc.) using sequences which have been already defined. Python supports the following 4 types of comprehensions:

What is comprehension in Python?

Comprehensions are constructs that allow sequences to be built from other sequences. Python 2.0 introduced list comprehensions and Python 3.0 comes with dictionary and set comprehensions.

What is a dictionary comprehension in Python?

Python Dictionary Comprehension. Dictionary comprehension is an elegant and concise way to create new dictionary from an iterable in Python. Dictionary comprehension consists of an expression pair (key: value) followed by for statement inside curly braces {}. Here is an example to make a dictionary with each item being a pair of a number and its square.

Does Someone use tuples in Python?

Tuples are used to store multiple items in a single variable. Tuple is one of 4 built-in data types in Python used to store collections of data, the other 3 are List, Set, and Dictionary, all with different qualities and usage. A tuple is a collection which is ordered and unchangeable. Tuples are written with round brackets.