Which of the following can be used to add a new column in existing dataframe:locatiloc<dataframe_object>.<column_lable>

The loc function in pandas is primarily used for accessing a group of rows and columns by labels or a boolean array. It is not typically used to add a new column in an existing dataframe.

However, you can add a new column to an existing dataframe in pandas using the following methods:

1. Direct assignment: This is the simplest way to add a new column. Here is an example:

dataframe['new_column_label'] = value

2. Using assign(): This function returns a new dataframe with the new column added to the old dataframe. Here is an example:

dataframe = dataframe.assign(new_column_label = value)

3. Using insert(): This function allows you to insert a column at a specific location. Here is an example:

dataframe.insert(location, 'new_column_label', value)

In all these examples, dataframe is your existing dataframe, new_column_label is the label of your new column, and value is the value(s) you want to add in the new column. The value can be a single value (which will be repeated for all rows), a list of values, or a Series object.