Q&A

Are list comprehensions bad?

Are list comprehensions bad?

It’s not considered bad. are generally frowned upon. In other words, readability is important. Basically, if you’re not storing the result, and/or it modifies some other object, then a list comprehension is probably a bad idea.

When should you use a generator instead of a list?

So what’s the difference between Generator Expressions and List Comprehensions? The generator yields one item at a time and generates item only when in demand. Whereas, in a list comprehension, Python reserves memory for the whole list. Thus we can say that the generator expressions are memory efficient than the lists.

What are the uses of list comprehensions feature of Python?

List comprehensions are used for creating new lists from other iterables like tuples, strings, arrays, lists, etc. A list comprehension consists of brackets containing the expression, which is executed for each element along with the for loop to iterate over each element.

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Should you use list comprehension?

List comprehensions are useful and can help you write elegant code that’s easy to read and debug, but they’re not the right choice for all circumstances. They might make your code run more slowly or use more memory.

Can we use assignment operator in list comprehension?

As mentioned in the above answers there is no direct assignment possible in the list comprehension feature, but there is a hackable way to do it using the exec method to achieve the assignment. Not just assignments we can pas any python expression in exec method to evaluate it.

Why tuples dont support comprehensions directly Unlike lists?

Comprehension works by looping or iterating over items and assigning them into a container, a Tuple is unable to receive assignments. Once a Tuple is created, it can not be appended to, extended, or assigned to.

Are Python generators slow?

the result is below. generator is so slower than other thing. Py2’s range() is a function that returns a list (which is iterable indeed but not an iterator), and xrange() is a class that implements the “iterable” protocol to lazily generate values during iteration but is not a generator either.

What are generator iterators list comprehension in Python?

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Generators allow you to create iterators in a very pythonic manner. Iterators allow lazy evaluation, only generating the next element of an iterable object when requested. This is useful for very large data sets. Iterators and generators can only be iterated over once.

What are some of the advantages of using list comprehensions?

The advantages of list comprehension are that it is less cumbersome than the for loop, can still be consolidated into an even more more concise format….When should list comprehension be used?

  • The code is more concise.
  • The code is generally more readable.
  • The code, in most cases, will run faster.

Why are list comprehensions faster than for loops?

List comprehension is faster because it is optimized for the Python interpreter to spot a predictable pattern during looping. Besides the syntactic benefit of list comprehensions, they are often as fast or faster than equivalent use of map .

What are the advantages of using list comprehensions?

The advantages of list comprehension are that it is less cumbersome than the for loop, can still be consolidated into an even more more concise format. The advantage is that it allows developers to write less code that is often easier to understand than other methods.

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Is it better to use list comprehension Python?

7 Answers. If the iteration is being done for its side effect ( as it is in your “print” example ), then a loop is clearer. If the iteration is executed in order to build a composite value, then list comprehensions are usually more readable.

What are the elements of a list in Python?

In Python programming, a list is created by placing all the items (elements) inside a square bracket [ ], separated by commas. It can have any number of items and they may be of different types (integer, float, string etc.).

What is a list comprehension?

A list comprehension is a syntactic construct available in some programming languages for creating a list based on existing lists.

What are some examples of Python?

Python is an example of a high-level language; other high-level languages you might have heard of are C++, PHP, and Java. As you might infer from the name high-level language, there are also low-level languages, sometimes referred to as machine languages or assembly languages.

What is Python comprehension?

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.