Get row index from DataFrame row

Question

Is it possible to get the row number (i.e. "the ordinal position of the index value") of a DataFrame row without adding an extra row that contains the row number (the index can be arbitrary, i.e. even a MultiIndex)?

>>> import pandas as pd
>>> df = pd.DataFrame({'a': [2, 3, 4, 2, 4, 6]})
>>> result = df[df.a > 3]
>>> result.iloc[0]
a    4
Name: 2, dtype: int64
# but how can I get the original row index of iloc[0] in df?

I could have done df['row_index'] = range(len(df)) which would maintain the original row number, but I am wondering if Pandas has a built-in way of doing this.

Answer 1

Access the .name attribute and use get_loc:

In [10]:
df.index.get_loc(result.iloc[0].name)

Out[10]:
2

Answer 2

Looking this from a different side:

for r in df.itertuples():
    getattr(r, 'Index')

Where df is the data frame. May be you want to use a conditional to get the index when a condition are met.