Are there alternative methods to creating an empty array then filling it in Python?

Question

I am new to Python but I have a decent amount of experience in Java and C, I am trying to create an array of a certain size then fill it with random numbers but no python tutorials about arrays mention methods about doing this (if I search explicitly about wanting that I get results that is not the problem) so I was wondering if that is considered a bad practice in Python and there are alternative ways to accomplishing what I want. Thank you.

Answer 1

Still to new to comment on @icejoywoo post ^

list are basically arrays for most purposes.

list comprehension is the easiest way to fill an array with lots of things

[ returnVal for i in range(10)]

any for loop or iterator will work return value itself can be a function

x= [None for i in range(10)]
[None,None..None]

x= [x**2 for i in range(10)]
[0,1,4..81]

y = lambda a: int((a**.5)*100)
x= [y(i) for i in range(10)]
[0, 100, 141, 173, 200, 223, 244, 264, 282, 300]

Answer 2

use random or numpy

In [1]: import random

In [2]: [random.random() for i in range(10)]
Out[2]:
[0.8233249954348517,
 0.6215056571076538,
 0.6273288221606772,
 0.12055176228045617,
 0.22782244162965615,
 0.9016145766629989,
 0.04615407289582629,
 0.8870216740449745,
 0.5622680783939463,
 0.9288600326401598]

In [3]: import numpy

In [4]: numpy.random.rand(5)
Out[4]: array([0.9288893 , 0.66600315, 0.82989425, 0.15717061, 0.33444802])

In [5]: list(numpy.random.rand(5))
Out[5]:
[0.46571036413626277,
 0.8268980751228664,
 0.9216520894106733,
 0.26706936577849916,
 0.47348417257319697]