In this article, we are going to see different methods to save an NumPy array into a CSV file. CSV file format is the easiest and useful format for storing data
There are different methods by which we can save the NumPy array into a CSV file
Method 1: Using Dataframe.to_csv().
This method is used to write a Dataframe into a CSV file.
Example: Converting the array into pandas Dataframe and then saving it to CSV format.
Python3
# import necessary librariesimport pandas as pdimport numpy as np # create a dummy arrayarr = np.arange(1,11).reshape(2,5) # display the arrayprint(arr) # convert array into dataframeDF = pd.DataFrame(arr) # save the dataframe as a csv fileDF.to_csv("data1.csv") |
Output:
[[ 1 2 3 4 5] [ 6 7 8 9 10]]
Method 2: Using numpy_array.tofile().
This method is used to write an array into the file.
Example: Create an array then save into a CSV file.
Python3
# import the necessary libraryimport numpy as np # create a dummy arrayarr = np.arange(1,11) # display the arrayprint(arr) # use the tofile() method # and use ',' as a separator# as we have to generate a csv filearr.tofile('data2.csv', sep = ',') |
Output:
[ 1 2 3 4 5 6 7 8 9 10]
Method 3: Using numpy.savetext().
This method is used to save an array to a text file.
Example: Create an array then save as a CSV file.
Python3
# import numpy libraryimport numpy # create an arraya = numpy.array([[1, 6, 4], [2, 4, 8], [3, 9, 1]]) # save array into csv filenumpy.savetxt("data3.csv", a, delimiter = ",") |
Output:
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