dask.bag.Bag.to_dataframe

Bag.to_dataframe(meta=None, columns=None)[source]

Create Dask Dataframe from a Dask Bag.

Bag should contain tuples, dict records, or scalars.

Index will not be particularly meaningful. Use reindex afterwards if necessary.

Parameters
metapd.DataFrame, dict, iterable, optional

An empty pd.DataFrame that matches the dtypes and column names of the output. This metadata is necessary for many algorithms in dask dataframe to work. For ease of use, some alternative inputs are also available. Instead of a DataFrame, a dict of {name: dtype} or iterable of (name, dtype) can be provided. If not provided or a list, a single element from the first partition will be computed, triggering a potentially expensive call to compute. This may lead to unexpected results, so providing meta is recommended. For more information, see dask.dataframe.utils.make_meta.

columnssequence, optional

Column names to use. If the passed data do not have names associated with them, this argument provides names for the columns. Otherwise this argument indicates the order of the columns in the result (any names not found in the data will become all-NA columns). Note that if meta is provided, column names will be taken from there and this parameter is invalid.

Examples

>>> import dask.bag as db
>>> b = db.from_sequence([{'name': 'Alice',   'balance': 100},
...                       {'name': 'Bob',     'balance': 200},
...                       {'name': 'Charlie', 'balance': 300}],
...                      npartitions=2)
>>> df = b.to_dataframe()
>>> df.compute()
      name  balance
0    Alice      100
1      Bob      200
0  Charlie      300