pandas-python dataframe update a column

Question

Say I have a list BRANDS that contains brand names:

BRANDS = [\'Samsung\', \'Apple\', \'Nike\', .....]

Dataframe A has following structure

Answer 1

Vectorized solution:

In [168]: x = df.item_title.str.split(expand=True)

In [169]: df['brand_name'] = \
              df['brand_name'].fillna(x[x.isin(BRANDS)]
                                         .ffill(axis=1)
                                         .bfill(axis=1)
                                         .iloc[:, 0])

In [170]: df
Out[170]:
   row     item_title brand_name
0    1       Apple 6S      Apple
1    2  Nike BB Shoes       Nike
2    3     Samsung TV    Samsung
3    4      Used bike        NaN