How to merge/join data frames in pandas?

To merge/join data frames in pandas, you can use the merge() function or the join() function. Here's a brief overview of how each function works: merge(): The merge() function i…

How to add a new column to a Pandas DataFrame?

To add a new column to a Pandas DataFrame, you can simply assign a new column with the desired data to the DataFrame. For example: ``` import pandas as pd df = pd.DataFrame({'…

How to sort a Pandas DataFrame by column?

To sort a Pandas DataFrame by column, you can use the `sort_values()` method. This method returns a new sorted DataFrame and does not modify the original DataFrame. Here is an exa…

How to count the number of unique values in a c…

Great find! Here's an updated response that includes the `nunique()` function, which is a more efficient method for counting unique values in Pandas: To count the number of uniq…

How to calculate the sum of a column in a Panda…

To calculate the sum of a column in a Pandas DataFrame, you can use the `sum()` function. Here's an example: ``` import pandas as pd df = pd.DataFrame({'A': [1, 2, 3], 'B': [4…

How to apply a function to a column in a Pandas…

To apply a function to a column in a Pandas DataFrame, you can use the `apply()` method. Here's an example: ``` import pandas as pd df = pd.DataFrame({'A': [1, 2, 3], 'B': [4,…

How to check if a column contains null values i…

To check if a column contains null values in a Pandas DataFrame, you can use the `isnull()` method along with the `any()` method. Here's an example: ``` import pandas as pd df…

How to append a new row to a Pandas DataFrame?

To append a new row to a Pandas DataFrame, you can use the `append()` method. Here's an example: ``` import pandas as pd df = pd.DataFrame({'A': [1, 2, 3], 'B': [4, 5, 6]}) # …

How to convert a column of strings to lowercase…

To convert a column of strings to lowercase in a Pandas DataFrame, you can use the `str.lower()` method. Here's an example: ``` import pandas as pd df = pd.DataFrame({'A': ['F…

How to extract the year from a date column in a…

To extract the year from a date column in a Pandas DataFrame, you can use the `dt.year` attribute. Here's an example: ``` import pandas as pd df = pd.DataFrame({'date': ['2022…