How-to articles, tricks, and solutions about PANDAS

You can use the .at or .iat methods to get the value of a specific cell in a DataFrame.

To change the size of figures drawn with Matplotlib in Python, you can use the figure() function and set the figsize argument.

You can use the isna() function to create a boolean mask of the NaN values in a column, and then use the sum() function to count the number of True values in the mask.

You can expand the output display of a Pandas DataFrame by setting the option 'display.max_columns' in pandas.

You can use the shape property of the DataFrame to get the number of rows and columns.

You can use the DataFrame.loc method to select rows from a DataFrame based on column values.

You can add a new column to an existing pandas DataFrame by using the assign() method or the [] notation.

In pandas, you can add an empty column to a DataFrame using the assign() method or the insert() method.

To apply a function to two columns of a Pandas DataFrame, you can use the apply() method of the DataFrame and pass the function as an argument.

To change the order of columns in a Pandas DataFrame, you can use the DataFrame's "reindex" method and specify the new order of the columns.

You can use the isna() method to check for NaN values in a Pandas DataFrame.

To convert the index of a pandas DataFrame into a column, you can use the reset_index() function, and specify that you want to move the index to a new column with the inplace=True and name parameter.

The "SettingWithCopyWarning" in pandas is raised when you try to modify a copy of a DataFrame or Series rather than the original.

You can drop rows of a Pandas DataFrame that have a NaN value in a certain column using the dropna() function.

You can filter a Pandas DataFrame using the isin() and ~(not in) methods.

You can use the iterrows() method to iterate over rows in a Pandas DataFrame.

You can replace NaN values in a column of a Pandas Dataframe by using the fillna() method and passing in the value you want to replace NaN with.

To sort a Pandas DataFrame based on the values in a column, you can use the sort_values() method of the DataFrame.

Here is an example code snippet that demonstrates how to use the groupby() method in pandas to group a DataFrame by two columns and get the counts for each group:

To set the name of the index column in a pandas DataFrame, you can use the .rename_axis() method or the .index.name attribute.

Here is an example of how to use the pd.merge() function to merge two DataFrames in pandas:

You can use the .head() method to print the first few rows of a Pandas Series or DataFrame in a "pretty" format.

You can use the .loc method to filter the DataFrame and get the boolean mask, and then use the .index property to get the index of the rows that match the certain value.

To rename the column names of a Pandas DataFrame, you can use the DataFrame.rename() method.

You can use the .iloc[] property to select a row by its integer index in a pandas DataFrame or Series.