pandas.DataFrame.iterrows — pandas 0.18.1 documentation (original) (raw)

DataFrame.iterrows()¶

Iterate over DataFrame rows as (index, Series) pairs.

See also

itertuples

Iterate over DataFrame rows as namedtuples of the values.

iteritems

Iterate over (column name, Series) pairs.

Notes

1. Because iterrows returns a Series for each row, it does not preserve dtypes across the rows (dtypes are preserved across columns for DataFrames). For example,

   df = pd.DataFrame([[1, 1.5]], columns=['int', 'float'])
   row = next(df.iterrows())[1]
   row
   int 1.0

float 1.5
Name: 0, dtype: float64

print(row['int'].dtype)
float64
print(df['int'].dtype)
int64
To preserve dtypes while iterating over the rows, it is better to use itertuples() which returns namedtuples of the values and which is generally faster than iterrows. 2. You should never modify something you are iterating over. This is not guaranteed to work in all cases. Depending on the data types, the iterator returns a copy and not a view, and writing to it will have no effect.