Passing array in python

Passing an array in Python to Django template

Let’s say that I had an array in the Python backend and wanted to pass it to the front end as json or a js array. How would I be able to do this using the Django framework? This is what the template might look like:

5 Answers 5

I try the answer, but the think that work by me was like:

from django.shortcuts import render_to_response from django.utils import simplejson def example_view(request): variable = <"myvar":[1, 2, 3]>render_to_response("example.html", simplejson.dumps(variable), context_instance=RequestContext(request)) 

In Django:
from django.utils import simplejson
json = simplejson.dumps(YOUR_VARIABLE)

IN JS:
var YOUR_JS_OBJECT = <>;

Full view so you get the idea:

from django.shortcuts import render_to_response from django.core import serializers def my_view(request) : json_data = serializers.serialize('json', my_django_object) render_to_response('my_template.html', ) 

haha I’ve actually never used them before. I just did a cursory search of the django docs for «json encode». I figured django probably had a fancy way of doing things.

I remember learning about them when I first studied about django. But since them I always used simplejson or even ‘str’ for that kind of need.

Django’s serializers only work for querysets. Any other type of data, and you need to use simplejson directly.

Daniel is right. About the performance, django uses a bundled version of simplejson, so there are no benefits of using simplejson directly.

Maybe you should read a django tutorial on how to pass variables from python to the template.

If your python list is a list of numbers, you could just use str or the module simplejson on it that it would be already a javascript array to use in your template.

import simplejson def example_view(request) variable = [1, 2, 3] return render(request, 'example.html', ) 

Источник

How to Pass an Array to a Function in Python?

Here, in this article let us look at how to pass an array to a function in Python.

In Python, any type of data, such as a text, list, array, dictionary, and so on, can be given as an argument to a function. When we send a numeric array as an argument to a Python method or function, it is passed by reference.

Function in Python:

A function is a block of code that only executes when it is invoked. Data, known as parameters, can be passed into a function. As a result, a function can return data.

A function is a set of related statements that accomplishes a certain task.

Functions help in the division of our program into smaller, modular parts. As our program increases in size, functions help to keep it organized and manageable.

It also avoids repetition and makes the code reusable.

Passing an Array to a Function in Python

Method #1: Using Built-in Functions (Static Input)

• Import all from array module using the import keyword
• Create a function say printing_array() which accepts the given aray as an argument
• Inside the function, loop in the above passed array using the for loop.
• Print each element of the given array.
• Pass ‘i’, some random list as arguments to the array() function to create an array.
• Store it in a variable.
• Here ‘i’ indicates the datatype of the given array elements is integer
• Pass the given array as an argument to the above-created printing_array() function to print an array.
• The Exit of the Program.

Below is the implementation:

# Import all from array module using the import keyword from array import * # Create a function say printing_array() which accepts the given aray as an argument def printing_array(arry): # Inside the function, loop in the above passed array using the for loop for k in arry: # Print each element of the given array. print(k) # Pass 'i', some random list as arguments to the array() function to create an array. # Store it in a variable. # Here 'i' indicates the datatype of the given array elements is integer gvn_arry = array('i', [1, 5, 3, 8, 2]) # Pass the given array as an argument to the above created printing_array() function # to print an array printing_array(gvn_arry)

Method #2: Using Built-in Functions (User Input)

• Import all from array module using the import keyword
• Create a function say printing_array() which accepts the given aray as an argument
• Inside the function, loop in the above passed array using the for loop.
• Print each element of the given array.
• Give the list as user input using the list(),map(),split(),int functions and store it in a variable.
• Pass ‘i’, above given list as arguments to the array() function to create an array.
• Store it in another variable.
• Here ‘i’ indicates the datatype of the given array elements is integer
• Pass the given array as an argument to the above-created printing_array() function to print an array.
• The Exit of the Program.

Below is the implementation:

# Import all from array module using the import keyword from array import * # Create a function say printing_array() which accepts the given aray as an argument def printing_array(arry): # Inside the function, loop in the above passed array using the for loop for k in arry: # Print each element of the given array. print(k) # Give the list as user input using the list(),map(),split(),int # functions and store it in a variable. gvn_lst = list(map(int, input( 'Enter some random List Elements separated by spaces = ').split())) # Pass 'i', above given list as arguments to the array() function to create an array. # Store it in another variable. # Here 'i' indicates the datatype of the given array elements is integer gvn_arry = array('i', gvn_lst) # Pass the given array as an argument to the above created printing_array() function # to print an array printing_array(gvn_arry)

Enter some random List Elements separated by spaces = 11 3 6 2 4 11 3 6 2 4

Источник

How to pass an array or a list into a function in python ?

Examples of how to pass an array or list as an argument of a function in python:

Pass a matrix in a function

In python, it is possible to pass a matrix as an argument of a function, example:

>>> import numpy as np >>> def function( x ): . return 0.5 * x + 2 . >>> x = np.arange(0,10,0.1) >>> y = function(x) >>> y array([ 2. , 2.05, 2.1 , 2.15, 2.2 , 2.25, 2.3 , 2.35, 2.4 , 2.45, 2.5 , 2.55, 2.6 , 2.65, 2.7 , 2.75, 2.8 , 2.85, 2.9 , 2.95, 3. , 3.05, 3.1 , 3.15, 3.2 , 3.25, 3.3 , 3.35, 3.4 , 3.45, 3.5 , 3.55, 3.6 , 3.65, 3.7 , 3.75, 3.8 , 3.85, 3.9 , 3.95, 4. , 4.05, 4.1 , 4.15, 4.2 , 4.25, 4.3 , 4.35, 4.4 , 4.45, 4.5 , 4.55, 4.6 , 4.65, 4.7 , 4.75, 4.8 , 4.85, 4.9 , 4.95, 5. , 5.05, 5.1 , 5.15, 5.2 , 5.25, 5.3 , 5.35, 5.4 , 5.45, 5.5 , 5.55, 5.6 , 5.65, 5.7 , 5.75, 5.8 , 5.85, 5.9 , 5.95, 6. , 6.05, 6.1 , 6.15, 6.2 , 6.25, 6.3 , 6.35, 6.4 , 6.45, 6.5 , 6.55, 6.6 , 6.65, 6.7 , 6.75, 6.8 , 6.85, 6.9 , 6.95]) 

x is a matrix and the function returns a new matrix y.

Note: it will return an error if a math function is used:

>>> import numpy as np >>> import math >>> def function( x ): . return math.cos(x) . >>> y = function(x) Traceback (most recent call last): File "", line 1, in File "", line 2, in function TypeError: only length-1 arrays can be converted to Python scalars 

>>> import numpy as np >>> def function( x ): . return np.cos(x) . >>> y = function(x) >>> y array([ 1. , 0.99500417, 0.98006658, 0.95533649, 0.92106099, 0.87758256, 0.82533561, 0.76484219, 0.69670671, 0.62160997, 0.54030231, 0.45359612, 0.36235775, 0.26749883, 0.16996714, 0.0707372 , -0.02919952, -0.12884449, -0.22720209, -0.32328957, -0.41614684, -0.5048461 , -0.58850112, -0.66627602, -0.73739372, -0.80114362, -0.85688875, -0.90407214, -0.94222234, -0.97095817, -0.9899925 , -0.99913515, -0.99829478, -0.98747977, -0.96679819, -0.93645669, -0.89675842, -0.84810003, -0.79096771, -0.7259323 , -0.65364362, -0.57482395, -0.49026082, -0.40079917, -0.30733287, -0.2107958 , -0.11215253, -0.01238866, 0.08749898, 0.18651237, 0.28366219, 0.37797774, 0.46851667, 0.55437434, 0.63469288, 0.70866977, 0.77556588, 0.83471278, 0.88551952, 0.92747843, 0.96017029, 0.98326844, 0.9965421 , 0.99985864, 0.99318492, 0.97658763, 0.95023259, 0.91438315, 0.86939749, 0.8157251 , 0.75390225, 0.68454667, 0.60835131, 0.52607752, 0.43854733, 0.34663532, 0.25125984, 0.15337386, 0.05395542, -0.04600213, -0.14550003, -0.24354415, -0.33915486, -0.43137684, -0.51928865, -0.6020119 , -0.67872005, -0.74864665, -0.81109301, -0.86543521, -0.91113026, -0.9477216 , -0.97484362, -0.99222533, -0.99969304, -0.99717216, -0.98468786, -0.96236488, -0.93042627, -0.88919115]) >>> 

 >>> l = ['coucou','hello','salut'] >>> def fonction(l): . for i in l: . print i . >>> fonction(l) coucou hello salut 

# Import all from array module using the import keyword from array import * # Create a function say printing_array() which accepts the given aray as an argument def printing_array(arry): # Inside the function, loop in the above passed array using the for loop for k in arry: # Print each element of the given array. print(k) # Pass 'i', some random list as arguments to the array() function to create an array. # Store it in a variable. # Here 'i' indicates the datatype of the given array elements is integer gvn_arry = array('i', [1, 5, 3, 8, 2]) # Pass the given array as an argument to the above created printing_array() function # to print an array printing_array(gvn_arry)

# Import all from array module using the import keyword from array import * # Create a function say printing_array() which accepts the given aray as an argument def printing_array(arry): # Inside the function, loop in the above passed array using the for loop for k in arry: # Print each element of the given array. print(k) # Give the list as user input using the list(),map(),split(),int # functions and store it in a variable. gvn_lst = list(map(int, input( 'Enter some random List Elements separated by spaces = ').split())) # Pass 'i', above given list as arguments to the array() function to create an array. # Store it in another variable. # Here 'i' indicates the datatype of the given array elements is integer gvn_arry = array('i', gvn_lst) # Pass the given array as an argument to the above created printing_array() function # to print an array printing_array(gvn_arry)

Enter some random List Elements separated by spaces = 11 3 6 2 4 11 3 6 2 4