Category: Python Answers

To get a list from Python Pandas DataFrame column headers, we call list on the data frame.

For instance, we write

list(my_dataframe)

where my_dataframe is a data frame to return a list.

To get the row count of a Python Pandas DataFrame, we can use various properties.

We can write one of

• len(df.index)
• df.shape[0]
• df[df.columns[0]].count()

to get the row count of a Pandas dataframe.

df is the dataframe.

To select multiple columns in a Python Pandas dataframe, we pass in an array of column names to select.

For instance, we write

df1 = df[['a', 'b']]

to select columns 'a' and 'b' and return it.

To delete a column from a Python Pandas DataFrame, we call the drop method.

For instance, we write

df = df.drop('column_name', 1)

to call df.drop to drop the column_name column only.

The 1 indicates we drop only the column in the 1st argument.

To rename column names in Python Pandas, we call the dataframe rename method.

For instance, we write

df = df.rename(columns={'oldName1': 'newName1', 'oldName2': 'newName2'})

to rename the oldName1 and oldName2 columns to newName1 and newName2 with df.rename.

And then we assign the returned dataframe back to df.