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=========
DataFrame
=========

DataFrame
---------

A :class:`~pyflink.dataframe.DataFrame` is the core abstraction of the PyFlink DataFrame API.
It wraps a PyFlink :class:`~pyflink.table.Table` and provides a pandas-like interface for
data transformations. All transformation methods return a new ``DataFrame`` (immutable/fluent API).

Example:
::

    >>> import pyflink.dataframe as pf
    >>> df = pf.from_dict({"a": [1, 2, 3], "b": ["x", "y", "z"]})
    >>> df.select("a", "b").filter(pf.col("a") > 1).collect()

.. currentmodule:: pyflink.dataframe.dataframe

.. autosummary::
    :toctree: api/

    DataFrame.select
    DataFrame.with_column
    DataFrame.with_columns
    DataFrame.drop_columns
    DataFrame.filter
    DataFrame.rename_columns
    DataFrame.group_by
    DataFrame.agg
    DataFrame.join
    DataFrame.map
    DataFrame.map_batches
    DataFrame.pipe
    DataFrame.limit
    DataFrame.offset
    DataFrame.head
    DataFrame.to_table
    DataFrame.to_pandas
    DataFrame.collect
    DataFrame.iter_rows
    DataFrame.iter_batches
    DataFrame.write_parquet
    DataFrame.write_kafka
    DataFrame.write_odps
    DataFrame.write_paimon
    DataFrame.write_sls
    DataFrame.write_hologres
    DataFrame.write_custom
    DataFrame.explain
    DataFrame.schema
    DataFrame.columns
    DataFrame.drop_null
    DataFrame.drop_nan
    DataFrame.fill_null
    DataFrame.fill_nan
    DataFrame.llm


GroupedDataFrame
----------------

A DataFrame that has been grouped on a set of grouping keys.

.. currentmodule:: pyflink.dataframe.dataframe

.. autosummary::
    :toctree: api/

    GroupedDataFrame.agg


Expressions
-----------

Helper functions to create column references and literal expressions.

.. currentmodule:: pyflink.dataframe.dataframe

.. autosummary::
    :toctree: api/

    col
    lit