How to Append Pandas DataFrame to Existing CSV File
by Abdul Rawoof A R Updated: Jan 31, 2023
You can use the pandas’ library in Python to append data to an existing table. Appending data to an existing table is a way to add new rows of data without modifying or deleting the existing data. This is helpful if you wish to update or add new data to a database while maintaining a historical record of the old data. append(): The append() method in pandas is used to add rows to a DataFrame, and return a new DataFrame with the newly added rows. The original DataFrame remains unchanged. The new DataFrame can be assigned to a variable, which can then be used for further processing or analysis.
- pd.concat(): pd.concat() is a function in the pandas library that is used to concatenate or join multiple DataFrames along a particular axis (axis=0 for rows and axis=1 for columns).
pd.concat() is similar to the append() method, but it can be used to concatenate DataFrames along either the rows or columns axis, and it can also take a list of DataFrames as input, whereas append() can only take one DataFrame at a time and concatenate along the rows axis.
For better knowledge of appending data in existing table using Pandas, you may have a look at the code below.
Fig : Preview of the output that you will get on running this code from your IDE.
In this solution we're using Pandas library.
import pandas as pd df = pd.DataFrame(columns=[str(i).zfill(2) for i in range(5)]) df.loc = range(5) # add row df.loc = range(5) # add row for i in range(len(df),len(df)+2): df.loc[i] = range(5) # add rows to end by starting at len(df) df 00 01 02 03 04 0 0.0 1.0 2.0 3.0 4.0 1 0.0 1.0 2.0 3.0 4.0 2 0.0 1.0 2.0 3.0 4.0 3 0.0 1.0 2.0 3.0 4.0
Follow the steps carefully to get the output easily.
- Install pandas on your IDE(Any of your favorite IDE).
- Copy the snippet using the 'copy' and paste it in your IDE.
- Add required dependencies and import them in Python file.
- Run the file to generate the output.
I hope you found this useful. I have added the link to dependent libraries, version information in the following sections.
I found this code snippet by searching for 'how to append data in existing table using pandas' in kandi. You can try any such use case!
I tested this solution in the following versions. Be mindful of changes when working with other versions.
- The solution is created in PyCharm 2021.3.
- The solution is tested on Python 3.9.7.
- Pandas version-v1.5.2.
Using this solution, we are able to append data in existing table using pandas with simple steps. This process also facilities an easy way to use, hassle-free method to create a hands-on working version of code which would help us to append data in existing table using pandas.
Flexible and powerful data analysis / manipulation library for Python, providing labeled data structures similar to R data.frame objects, statistical functions, and much more
Python 38499 Version:v2.0.2 License: Permissive (BSD-3-Clause)
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