👀 Views: 82 💬 Answers: 1 📅 Created: 2025-06-12

pandas merge typeerror Python

Hey everyone, I'm running into an issue that's driving me crazy... I'm currently working on a data processing script using pandas version 1.3.2 in Python 3.9, and I'm working with a `TypeError` when trying to merge two dataframes that have nullable integer columns. The behavior message I'm receiving is: ``` TypeError: merge() got an unexpected keyword argument 'on' ``` I've defined two dataframes like so: ```python import pandas as pd df1 = pd.DataFrame({ 'id': [1, 2, 3], 'value': [10, None, 30] }) df2 = pd.DataFrame({ 'id': [1, 2, 4], 'value': [100, 200, 400] }) ``` I intended to merge these two dataframes on the 'id' column. However, when I try to execute: ```python merged_df = pd.merge(df1, df2, on='id') ``` I get the `TypeError`. I've checked to ensure both 'id' columns are of the same type (both are integers). To troubleshoot, I tested merging without specifying the `on` parameter: ```python merged_df = pd.merge(df1, df2) ``` This worked fine and returned a merged dataframe, but it's not clear why specifying the `on` parameter causes the scenario. I also tried converting the 'id' columns to a different dtype (`str`), but that didn't help either. Can anyone explain why this behavior occurs and how I can merge the dataframes correctly while keeping the `on` parameter? Any insights would be appreciated! For context: I'm using Python on Windows. What's the best practice here? Am I missing something obvious? This is happening in both development and production on Ubuntu 20.04. Thanks in advance!