Python Array Data Structure

A Python Array Data Structure is an array data structure that is a Python data structure.

• Context:
  • It can range from being a Python Built-In Array to being a Python Library Array to being a Python Custom Array.
  • It can support a Python Array Operation.
  • It can be the input to an Array-input Python Subroutine, such as a Python Join Subroutine.
  • It can range from being
    • a Python Tuple,
    • a Python Vector,
    • a Python Array of Arrays, such as a Python Matrix,
    • a Python Array of Hashes.
• Example(s):
  • a Python List Data Structure.
  • a Numpy Matrix Data Structure.
  • a Numpy Array.
  • a Pandas DataFrame Data Structure.
  • …
• Counter-Example(s):
  • a Python Dictionary Data Structure.
  • a Perl Array Data Structure.
• See: Python Coding Example, Python Built-In Datatype.

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References

• https://docs.python.org/2/library/array.html

Examples

Import libraries

import numpy as np
import pandas as pd

Empty array

df = pd.DataFrame(columns=['col1','col2'])
df = pd.DataFrame(np.zeros(0, dtype=[('col1', 'i7'),('col2', 'a50')]))

Populate manually

Matrix = [ [0 for x in xrange(5)] for y in xrange(6)] 
Matrix[4][3] = 99
Matrix

xx =  np.array([2, 4, -11])
yy = zeros(3, Int)        # Create empty array ready to receive result

Populate from a file.

Loops

for i in range(0, 3):
  Matrix[i] = i * 2
print yy
#    [  4   8 -22]

Transforming into a string

Emptying

Random

import random;
#Generate 1000 random integer numbers which are between 1 and 9999(included).
Z=random.sample(range(1,9999),1000);
type(Z)

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