how to make a column by using another column as a filter in python code example

Example 1: pandas filter rows by value in list

df.loc[df['col name'].isin(ls_conditions)]

Example 2: pandas filter rows by value

# does year equals to 2002?
# is_2002 is a boolean variable with True or False in it
>is_2002 =  gapminder['year']==2002
>print(is_2002.head())
0    False
1    False
2    False
3    False
4    False
# filter rows for year 2002 using  the boolean variable
>gapminder_2002 = gapminder[is_2002]
>print(gapminder_2002.shape)
(142, 6)