df[df['column_name'] == 'what to search for']
With AND and OR logical operators:
df[df[('column_name'] == 'what to search for') & ('column_name'] == 'what to search for')]
df[df[('column_name'] == 'what to search for') | ('column_name'] == 'what to search for')]
df[df['column_name'].str.contains('substring to look for')]
[x[0], x[1],...x[n] for x in zip(df['col1'], df['col2'], ... df['coln'])]