pandas.DataFrame.groupby
DataFrame.groupby(self, by=None, axis=0, level=None, as_index: bool = True, sort: bool = True, group_keys: bool = True, squeeze: bool = False, observed: bool = False) → ’groupby_generic.DataFrameGroupBy’[source]
Group DataFrame using a mapper or by a Series of columns.
A groupby operation involves some combination of splitting the object, applying a function, and combining the results. This can be used to group large amounts of data and compute operations on these groups.
Parameters
by mapping, function, label, or list of labels
Used to determine the groups for the groupby. If by is a function, it’s called on each value of the object’s index. If a dict or Series is passed, the Series or dict VALUES will be used to determine the groups (the Series’ values are first aligned; see .align() method). If an ndarray is passed, the values are used as-is determine the groups. A label or list of labels may be passed to group by the columns in self. Notice that a tuple is interpreted as a (single) key.
axis{0 or ‘index’, 1 or ‘columns’}, default 0
Split along rows (0) or columns (1).
level int, level name, or sequence of such, default None
If the axis is a MultiIndex (hierarchical), group by a particular level or levels.
as_index bool, default True
For aggregated output, return object with group labels as the index. Only relevant for DataFrame input. as_index=False is effectively “SQL-style” grouped output.
sort bool, default True
Sort group keys. Get better performance by turning this off. Note this does not influence the order of observations within each group. Groupby preserves the order of rows within each group.
group_keys bool, default True
When calling apply, add group keys to index to identify pieces.
squeeze bool, default False
Reduce the dimensionality of the return type if possible, otherwise return a consistent type.
observed bool, default False
The github link for this video is below 👇👇
[ Ссылка ]
This only applies if any of the groupers are Categoricals. If True: only show observed values for categorical groupers. If False: show all values for categorical groupers.
New in version 0.23.0.
Returns
DataFrameGroupBy
Returns a groupby object that contains information about the groups.
