What is an array in Python How to declare it

Question

I am unable to find arrays in the python documentation. How can I declare an array in Python?

Answer 1

Python doesn't have a native array data structure, but it has the "list". In Python list, you can store elements of different types whereas in array all the elements should of the same type.

List is the most versatile datatype available in Python which can be written as a list of comma-separated values (items) between square brackets. Also in Python, there is a powerful N-dimension array object called as Numpy, which is in the form of rows and columns. You can initialize numpy arrays from nested Python lists and access it elements.

Consider the example below to declare a list:

Subjects = ['Physics', 'Chemistry', 'Maths', 2]
print(Subjects)

Notice that the Subjects List contains both words as well as numbers.

Answer 2

variable = []

Now variable refers to an empty list^*.

Of course this is an assignment, not a declaration. There's no way to say in Python "this variable should never refer to anything other than a list", since Python is dynamically typed.

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^*The default built-in Python type is called a list, not an array. It is an ordered container of arbitrary length that can hold a heterogenous collection of objects (their types do not matter and can be freely mixed). This should not be confused with the array module, which offers a type closer to the C array type; the contents must be homogenous (all of the same type), but the length is still dynamic.

Answer 3

You don't actually declare things, but this is how you create an array in Python:

from array import array
intarray = array('i')

For more info see the array module: http://docs.python.org/library/array.html

Now possible you don't want an array, but a list, but others have answered that already. :)

Answer 4

I think you (meant)want an list with the first 30 cells already filled. So

   f = []

   for i in range(30):
       f.append(0)

An example to where this could be used is in Fibonacci sequence.

Answer 5

This is how:

my_array = [1, 'rebecca', 'allard', 15]

Answer 6

Python calls them lists. You can write a list literal with square brackets and commas:

>>> [6,28,496,8128]
[6, 28, 496, 8128]

Answer 7

Arrays are popular in most programming languages like: Java, C/C++, JavaScript etc. In python not Array Concept. Here We Discuss About Python List.We can treat lists as arrays. However, we cannot constrain the type of elements stored in a list. For example:

           x= [1, 2, "Hello"]