find rows with exact match of string in pandas code example

Example: pandas df exact equals

>>> from pandas._testing import assert_frame_equal
>>> df1 = pd.DataFrame({'a': [1, 2], 'b': [3, 4]})
>>> df2 = pd.DataFrame({'a': [1, 2], 'b': [3.0, 4.0]})
>>> df3 = pd.DataFrame({'a': [1, 2], 'b': [3.0, 4.0]})
>>> assert_frame_equal(df1, df2)
False
>>> assert_frame_equal(df2, df3)
True
>>> assert_frame_equal(df1, df2, check_dtype=False)
True