Appen Column to Existing CSV File in Python (Example Code)
In this tutorial, I’ll demonstrate how to add a new column to a CSV file in the Python programming language.
Setting up the Example
import pandas as pd # Load pandas library |
import pandas as pd # Load pandas library
my_df = pd.DataFrame({'A':range(0, 5), # Construct pandas DataFrame in Python 'B':['x', 'y', 'x', 'x', 'y'], 'C':range(15, 10, - 1)}) print(my_df) # A B C # 0 0 x 15 # 1 1 y 14 # 2 2 x 13 # 3 3 x 12 # 4 4 y 11 |
my_df = pd.DataFrame({'A':range(0, 5), # Construct pandas DataFrame in Python 'B':['x', 'y', 'x', 'x', 'y'], 'C':range(15, 10, - 1)}) print(my_df) # A B C # 0 0 x 15 # 1 1 y 14 # 2 2 x 13 # 3 3 x 12 # 4 4 y 11
my_df.to_csv('my_df.csv', index = False) # Saving pandas DataFrame as CSV |
my_df.to_csv('my_df.csv', index = False) # Saving pandas DataFrame as CSV
Example: Appending a New Column to a pandas DataFrame in a CSV File
col_D = ['x', 'x', 'y', 'y', 'x'] # Create new variable print(col_D) # ['x', 'x', 'y', 'y', 'x'] |
col_D = ['x', 'x', 'y', 'y', 'x'] # Create new variable print(col_D) # ['x', 'x', 'y', 'y', 'x']
my_df_add = pd.read_csv('my_df.csv') # Importing CSV file |
my_df_add = pd.read_csv('my_df.csv') # Importing CSV file
my_df_add['D'] = col_D # Adding list to DataFrame |
my_df_add['D'] = col_D # Adding list to DataFrame
my_df_add.to_csv('my_df_add.csv') # Saving updated DataFrame |
my_df_add.to_csv('my_df_add.csv') # Saving updated DataFrame
Related Tutorials & Further Resources
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