filter dataframe by contents code example

Example 1: pandas filter rows by value in list

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

Example 2: pandas column filter

filter = df['column']!= 0
df = df[filter]

Example 3: 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)

Example 4: filter one dataframe by another

df1 = pd.DataFrame({'c': ['A', 'A', 'B', 'C', 'C'],
                    'k': [1, 2, 2, 2, 2],
                    'l': ['a', 'b', 'a', 'a', 'd']})
df2 = pd.DataFrame({'c': ['A', 'C'],
                    'l': ['b', 'a']})
keys = list(df2.columns.values)
i1 = df1.set_index(keys).index
i2 = df2.set_index(keys).index
df1[~i1.isin(i2)]