numpy.column_stack() in Python Last Updated : 06 Jan, 2019 Comments Improve Suggest changes Like Article Like Report numpy.column_stack() function is used to stack 1-D arrays as columns into a 2-D array.It takes a sequence of 1-D arrays and stack them as columns to make a single 2-D array. 2-D arrays are stacked as-is, just like with hstack function. Syntax : numpy.column_stack(tup) Parameters : tup : [sequence of ndarrays] Tuple containing arrays to be stacked. The arrays must have the same first dimension. Return : [stacked 2-D array] The stacked 2-D array of the input arrays. Code #1 : Python3 # Python program explaining # column_stack() function import numpy as geek # input array in_arr1 = geek.array(( 1, 2, 3 )) print ("1st Input array : \n", in_arr1) in_arr2 = geek.array(( 4, 5, 6 )) print ("2nd Input array : \n", in_arr2) # Stacking the two arrays out_arr = geek.column_stack((in_arr1, in_arr2)) print ("Output stacked array:\n ", out_arr) Output: 1st Input array : [1 2 3] 2nd Input array : [4 5 6] Output stacked array: [[1 4] [2 5] [3 6]] Code #2 : Python3 # Python program explaining # column_stack() function import numpy as geek # input array in_arr1 = geek.array([[ 1, 2, 3], [ -1, -2, -3]] ) print ("1st Input array : \n", in_arr1) in_arr2 = geek.array([[ 4, 5, 6], [ -4, -5, -6]] ) print ("2nd Input array : \n", in_arr2) # Stacking the two arrays out_arr = geek.column_stack((in_arr1, in_arr2)) print ("Output stacked array :\n ", out_arr) Output: 1st Input array : [[ 1 2 3] [-1 -2 -3]] 2nd Input array : [[ 4 5 6] [-4 -5 -6]] Output stacked array : [[ 1 2 3 4 5 6] [-1 -2 -3 -4 -5 -6]] Comment More info J jana_sayantan Follow Improve Article Tags : Python Python-numpy Python numpy-arrayManipulation Explore Python FundamentalsPython Introduction 3 min read Input and Output in Python 4 min read Python Variables 5 min read Python Operators 5 min read Python Keywords 2 min read Python Data Types 7 min read Conditional Statements in Python 3 min read Loops in Python - For, While and Nested Loops 6 min read Python Functions 5 min read Recursion in Python 4 min read Python Lambda Functions 5 min read Python Data StructuresPython String 5 min read Python Lists 4 min read Python Tuples 4 min read Python Dictionary 3 min read Python Sets 6 min read Python Arrays 7 min read List Comprehension in Python 4 min read Advanced PythonPython OOP Concepts 11 min read Python Exception Handling 5 min read File Handling in Python 4 min read Python Database Tutorial 4 min read Python MongoDB Tutorial 2 min read Python MySQL 9 min read Python Packages 12 min read Python Modules 7 min read Python DSA Libraries 15 min read List of Python GUI Library and Packages 3 min read Data Science with PythonNumPy Tutorial - Python Library 3 min read Pandas Tutorial 6 min read Matplotlib Tutorial 5 min read Python Seaborn Tutorial 15+ min read StatsModel Library- Tutorial 4 min read Learning Model Building in Scikit-learn 8 min read TensorFlow Tutorial 2 min read PyTorch Tutorial 7 min read Web Development with PythonFlask Tutorial 8 min read Django Tutorial | Learn Django Framework 7 min read Django ORM - Inserting, Updating & Deleting Data 4 min read Templating With Jinja2 in Flask 6 min read Django Templates 7 min read Python | Build a REST API using Flask 3 min read How to Create a basic API using Django Rest Framework ? 4 min read Python PracticePython Quiz 3 min read Python Coding Practice 1 min read Python Interview Questions and Answers 15+ min read Like