Class SeriesGroupBy (2.0.0) 

SeriesGroupBy(
    block: bigframes.core.blocks.Block,
    value_column: str,
    by_col_ids: typing.Sequence[str],
    value_name: typing.Hashable = None,
    dropna=True,
)

Class for grouping and aggregating relational data.

Methods

agg

agg(
    func=None,
) -> typing.Union[bigframes.dataframe.DataFrame, bigframes.series.Series]

Aggregate using one or more operations.

Examples:

>>> import bigframes.pandas as bpd
>>> import numpy as np
>>> bpd.options.display.progress_bar = None

>>> s = bpd.Series([1, 2, 3, 4], index=[1, 1, 2, 2])
>>> s.groupby(level=0).agg(['min', 'max'])
   min  max
1    1    2
2    3    4
<BLANKLINE>
[2 rows x 2 columns]
Returns
Type Description
bigframes.pandas.Series A BigQuery Series.

aggregate

aggregate(
    func=None,
) -> typing.Union[bigframes.dataframe.DataFrame, bigframes.series.Series]

Aggregate using one or more operations.

Examples:

>>> import bigframes.pandas as bpd
>>> import numpy as np
>>> bpd.options.display.progress_bar = None

>>> s = bpd.Series([1, 2, 3, 4], index=[1, 1, 2, 2])
>>> s.groupby(level=0).aggregate(['min', 'max'])
   min  max
1    1    2
2    3    4
<BLANKLINE>
[2 rows x 2 columns]
Returns
Type Description
bigframes.pandas.Series A BigQuery Series.

all

all() -> bigframes.series.Series

Return True if all values in the group are true, else False.

Examples:

For SeriesGroupBy:

>>> import bigframes.pandas as bpd
>>> bpd.options.display.progress_bar = None

>>> lst = ['a', 'a', 'b']
>>> ser = bpd.Series([1, 2, 0], index=lst)
>>> ser.groupby(level=0).all()
a     True
b    False
dtype: boolean

For DataFrameGroupBy:

>>> data = [[1, 0, 3], [1, 5, 6], [7, 8, 9]]
>>> df = bpd.DataFrame(data, columns=["a", "b", "c"],
...                    index=["ostrich", "penguin", "parrot"])
>>> df.groupby(by=["a"]).all()
        b       c
a
1   False    True
7   True    True
<BLANKLINE>
[2 rows x 2 columns]
Returns
Type Description
bigframes.pandas.DataFrame or bigframes.pandas.Series DataFrame or Series of boolean values, where a value is True if all elements are True within its respective group; otherwise False.

any

any() -> bigframes.series.Series

Return True if any value in the group is true, else False.

Examples:

For SeriesGroupBy:

>>> import bigframes.pandas as bpd
>>> bpd.options.display.progress_bar = None

>>> lst = ['a', 'a', 'b']
>>> ser = bpd.Series([1, 2, 0], index=lst)
>>> ser.groupby(level=0).any()
a     True
b    False
dtype: boolean

For DataFrameGroupBy:

>>> data = [[1, 0, 3], [1, 0, 6], [7, 1, 9]]
>>> df = bpd.DataFrame(data, columns=["a", "b", "c"],
...                    index=["ostrich", "penguin", "parrot"])
>>> df.groupby(by=["a"]).any()
        b       c
a
1   False    True
7   True    True
<BLANKLINE>
[2 rows x 2 columns]
Returns
Type Description
bigframes.pandas.DataFrame or bigframes.pandas.Series DataFrame or Series of boolean values, where a value is True if any element is True within its respective group; otherwise False.

count

count() -> bigframes.series.Series

Compute count of group, excluding missing values.

Examples:

For SeriesGroupBy:

>>> import bigframes.pandas as bpd
>>> import numpy as np
>>> bpd.options.display.progress_bar = None

>>> lst = ['a', 'a', 'b']
>>> ser = bpd.Series([1, 2, np.nan], index=lst)
>>> ser.groupby(level=0).count()
a     2
b     0
dtype: Int64

For DataFrameGroupBy:

>>> data = [[1, np.nan, 3], [1, np.nan, 6], [7, 8, 9]]
>>> df = bpd.DataFrame(data, columns=["a", "b", "c"],
...                    index=["cow", "horse", "bull"])
>>> df.groupby(by=["a"]).count()
   b  c
a
1  0  2
7  1  1
<BLANKLINE>
[2 rows x 2 columns]
Returns
Type Description
bigframes.pandas.DataFrame or bigframes.pandas.Series Count of values within each group.

cumcount

cumcount(*args, **kwargs) -> bigframes.series.Series

Number each item in each group from 0 to the length of that group - 1. (DataFrameGroupBy functionality is not yet available.)

Examples:

For SeriesGroupBy:

>>> import bigframes.pandas as bpd
>>> bpd.options.display.progress_bar = None

>>> lst = ['a', 'a', 'b', 'b', 'c']
>>> ser = bpd.Series([5, 1, 2, 3, 4], index=lst)
>>> ser.groupby(level=0).cumcount()
a    0
a    1
b    0
b    1
c    0
dtype: Int64
>>> ser.groupby(level=0).cumcount(ascending=False)
a    0
a    1
b    0
b    1
c    0
dtype: Int64
Parameter
Name Description
ascending bool, default True

If False, number in reverse, from length of group - 1 to 0.
Returns
Type Description
bigframes.pandas.Series Sequence number of each element within each group.

cummax

cummax(*args, **kwargs) -> bigframes.series.Series

Cumulative max for each group.

Examples:

For SeriesGroupBy:

>>> import bigframes.pandas as bpd
>>> import numpy as np
>>> bpd.options.display.progress_bar = None

>>> lst = ['a', 'a', 'b']
>>> ser = bpd.Series([6, 2, 0], index=lst)
>>> ser.groupby(level=0).cummax()
a    6
a    6
b    0
dtype: Int64

For DataFrameGroupBy:

>>> data = [[1, 8, 2], [1, 2, 5], [2, 6, 9]]
>>> df = bpd.DataFrame(data, columns=["a", "b", "c"],
...                   index=["fox", "gorilla", "lion"])
>>> df.groupby("a").cummax()
         b  c
fox      8  2
gorilla  8  5
lion     6  9
<BLANKLINE>
[3 rows x 2 columns]
Returns
Type Description
bigframes.pandas.DataFrame or bigframes.pandas.Series Cumulative max for each group.

cummin

cummin(*args, **kwargs) -> bigframes.series.Series

Cumulative min for each group.

Examples:

For SeriesGroupBy:

>>> import bigframes.pandas as bpd
>>> import numpy as np
>>> bpd.options.display.progress_bar = None

>>> lst = ['a', 'a', 'b']
>>> ser = bpd.Series([6, 2, 0], index=lst)
>>> ser.groupby(level=0).cummin()
a    6
a    2
b    0
dtype: Int64

For DataFrameGroupBy:

>>> data = [[1, 8, 2], [1, 2, 5], [2, 6, 9]]
>>> df = bpd.DataFrame(data, columns=["a", "b", "c"],
...                   index=["fox", "gorilla", "lion"])
>>> df.groupby("a").cummin()
         b  c
fox      8  2
gorilla  2  2
lion     6  9
<BLANKLINE>
[3 rows x 2 columns]
Returns
Type Description
bigframes.pandas.DataFrame or bigframes.pandas.Series Cumulative min for each group.

cumprod

cumprod(*args, **kwargs) -> bigframes.series.Series

Cumulative product for each group.

Examples:

For SeriesGroupBy:

>>> import bigframes.pandas as bpd
>>> import numpy as np
>>> bpd.options.display.progress_bar = None

>>> lst = ['a', 'a', 'b']
>>> ser = bpd.Series([6, 2, 0], index=lst)
>>> ser.groupby(level=0).cumprod()
a     6.0
a    12.0
b     0.0
dtype: Float64

For DataFrameGroupBy:

>>> data = [[1, 8, 2], [1, 2, 5], [2, 6, 9]]
>>> df = bpd.DataFrame(data, columns=["a", "b", "c"],
...                   index=["cow", "horse", "bull"])
>>> df.groupby("a").cumprod()
          b     c
cow     8.0   2.0
horse  16.0  10.0
bull    6.0   9.0
<BLANKLINE>
[3 rows x 2 columns]
Returns
Type Description
bigframes.pandas.DataFrame or bigframes.pandas.Series Cumulative product for each group.

cumsum

cumsum(*args, **kwargs) -> bigframes.series.Series

Cumulative sum for each group.

Examples:

For SeriesGroupBy:

>>> import bigframes.pandas as bpd
>>> import numpy as np
>>> bpd.options.display.progress_bar = None

>>> lst = ['a', 'a', 'b']
>>> ser = bpd.Series([6, 2, 0], index=lst)
>>> ser.groupby(level=0).cumsum()
a    6
a    8
b    0
dtype: Int64

For DataFrameGroupBy:

>>> data = [[1, 8, 2], [1, 2, 5], [2, 6, 9]]
>>> df = bpd.DataFrame(data, columns=["a", "b", "c"],
...                   index=["fox", "gorilla", "lion"])
>>> df.groupby("a").cumsum()
          b  c
fox       8  2
gorilla  10  7
lion      6  9
<BLANKLINE>
[3 rows x 2 columns]
Returns
Type Description
bigframes.pandas.DataFrame or bigframes.pandas.Series Cumulative sum for each group.

diff

diff(periods=1) -> bigframes.series.Series

First discrete difference of element. Calculates the difference of each element compared with another element in the group (default is element in previous row).

Examples:

For SeriesGroupBy:

>>> import bigframes.pandas as bpd
>>> import numpy as np
>>> bpd.options.display.progress_bar = None

>>> lst = ['a', 'a', 'a', 'b', 'b', 'b']
>>> ser = bpd.Series([7, 2, 8, 4, 3, 3], index=lst)
>>> ser.groupby(level=0).diff()
a    <NA>
a      -5
a       6
b    <NA>
b      -1
b       0
dtype: Int64

For DataFrameGroupBy:

>>> data = {'a': [1, 3, 5, 7, 7, 8, 3], 'b': [1, 4, 8, 4, 4, 2, 1]}
>>> df = bpd.DataFrame(data, index=['dog', 'dog', 'dog',
...                   'mouse', 'mouse', 'mouse', 'mouse'])
>>> df.groupby(level=0).diff()
          a     b
dog    <NA>  <NA>
dog       2     3
dog       2     4
mouse  <NA>  <NA>
mouse     0     0
mouse     1    -2
mouse    -5    -1
<BLANKLINE>
[7 rows x 2 columns]
Returns
Type Description
bigframes.pandas.DataFrame or bigframes.pandas.Series First differences.

expanding

expanding(min_periods: int = 1) -> bigframes.core.window.rolling.Window

Provides expanding functionality.

Examples:

>>> import bigframes.pandas as bpd
>>> import numpy as np
>>> bpd.options.display.progress_bar = None

>>> lst = ['a', 'a', 'c', 'c', 'e']
>>> ser = bpd.Series([1, 0, -2, -1, 2], index=lst)
>>> ser.groupby(level=0).expanding().min()
index  index
a      a         1
       a         0
c      c        -2
       c        -2
e      e         2
dtype: Int64
Returns
Type Description
bigframes.pandas.DataFrame or bigframes.pandas.Series An expanding grouper, providing expanding functionality per group.

head

head(n: int = 5) -> bigframes.series.Series

Return last first n rows of each group

Examples:

>>> import bigframes.pandas as bpd
>>> bpd.options.display.progress_bar = None

>>> df = bpd.DataFrame([[1, 2], [1, 4], [5, 6]],
...                   columns=['A', 'B'])
>>> df.groupby('A').head(1)
   A  B
0  1  2
2  5  6
[2 rows x 2 columns]
Parameter
Name Description
n int

If positive: number of entries to include from start of each group. If negative: number of entries to exclude from end of each group.
Returns
Type Description
bigframes.pandas.DataFrame or bigframes.pandas.Series First n rows of the original DataFrame or Series

kurt

kurt(*args, **kwargs) -> bigframes.series.Series

Return unbiased kurtosis over requested axis.

Kurtosis obtained using Fisher's definition of kurtosis (kurtosis of normal == 0.0). Normalized by N-1.

Examples:

>>> import bigframes.pandas as bpd
>>> bpd.options.display.progress_bar = None

>>> lst = ['a', 'a', 'a', 'a', 'b', 'b', 'b', 'b', 'b']
>>> ser = bpd.Series([0, 1, 1, 0, 0, 1, 2, 4, 5], index=lst)
>>> ser.groupby(level=0).kurt()
a        -6.0
b   -1.963223
dtype: Float64
Parameter
Name Description
numeric_only bool, default False

Include only float, int or boolean data.
Returns
Type Description
bigframes.pandas.DataFrame or bigframes.pandas.Series Variance of values within each group.

kurtosis

kurtosis(*args, **kwargs) -> bigframes.series.Series

Return unbiased kurtosis over requested axis.

Kurtosis obtained using Fisher's definition of kurtosis (kurtosis of normal == 0.0). Normalized by N-1.

Examples:

>>> import bigframes.pandas as bpd
>>> bpd.options.display.progress_bar = None

>>> lst = ['a', 'a', 'a', 'a', 'b', 'b', 'b', 'b', 'b']
>>> ser = bpd.Series([0, 1, 1, 0, 0, 1, 2, 4, 5], index=lst)
>>> ser.groupby(level=0).kurtosis()
a        -6.0
b   -1.963223
dtype: Float64
Parameter
Name Description
numeric_only bool, default False

Include only float, int or boolean data.
Returns
Type Description
bigframes.pandas.DataFrame or bigframes.pandas.Series Variance of values within each group.

max

max(*args) -> bigframes.series.Series

Compute max of group values.

Examples:

For SeriesGroupBy:

>>> import bigframes.pandas as bpd
>>> bpd.options.display.progress_bar = None

>>> lst = ['a', 'a', 'b', 'b']
>>> ser = bpd.Series([1, 2, 3, 4], index=lst)
>>> ser.groupby(level=0).max()
a     2
b     4
dtype: Int64

For DataFrameGroupBy:

>>> data = [[1, 8, 2], [1, 2, 5], [2, 5, 8], [2, 6, 9]]
>>> df = bpd.DataFrame(data, columns=["a", "b", "c"],
...                    index=["tiger", "leopard", "cheetah", "lion"])
>>> df.groupby(by=["a"]).max()
   b  c
a
1  8  5
2  6  9
<BLANKLINE>
[2 rows x 2 columns]
Parameters
Name Description
numeric_only bool, default False

Include only float, int, boolean columns.
min_count int, default 0

The required number of valid values to perform the operation. If fewer than min_count and non-NA values are present, the result will be NA.
Returns
Type Description
bigframes.pandas.DataFrame or bigframes.pandas.Series Computed max of values within each group.

mean

mean(*args) -> bigframes.series.Series

Compute mean of groups, excluding missing values.

Examples:

>>> import bigframes.pandas as bpd
>>> import numpy as np
>>> bpd.options.display.progress_bar = None
>>> df = bpd.DataFrame({'A': [1, 1, 2, 1, 2],
...                    'B': [np.nan, 2, 3, 4, 5],
...                    'C': [1, 2, 1, 1, 2]}, columns=['A', 'B', 'C'])

Groupby one column and return the mean of the remaining columns in each group.

>>> df.groupby('A').mean()
    B         C
A
1  3.0  1.333333
2  4.0       1.5
<BLANKLINE>
[2 rows x 2 columns]

Groupby two columns and return the mean of the remaining column.

>>> df.groupby(['A', 'B']).mean()
         C
A B
1 2.0  2.0
  4.0  1.0
2 3.0  1.0
  5.0  2.0
<BLANKLINE>
[4 rows x 1 columns]

Groupby one column and return the mean of only particular column in the group.

>>> df.groupby('A')['B'].mean()
A
1    3.0
2    4.0
Name: B, dtype: Float64
Parameter
Name Description
numeric_only bool, default False

Include only float, int, boolean columns.
Returns
Type Description
bigframes.pandas.DataFrame or bigframes.pandas.Series Mean of groups.

median

median(*args, exact: bool = True, **kwargs) -> bigframes.series.Series

Compute median of groups, excluding missing values.

Examples:

For SeriesGroupBy:

>>> import bigframes.pandas as bpd
>>> import numpy as np
>>> bpd.options.display.progress_bar = None

>>> lst = ['a', 'a', 'a', 'b', 'b', 'b']
>>> ser = bpd.Series([7, 2, 8, 4, 3, 3], index=lst)
>>> ser.groupby(level=0).median()
a    7.0
b    3.0
dtype: Float64

For DataFrameGroupBy:

>>> data = {'a': [1, 3, 5, 7, 7, 8, 3], 'b': [1, 4, 8, 4, 4, 2, 1]}
>>> df = bpd.DataFrame(data, index=['dog', 'dog', 'dog',
...                    'mouse', 'mouse', 'mouse', 'mouse'])
>>> df.groupby(level=0).median()
        a    b
dog    3.0  4.0
mouse  7.0  3.0
<BLANKLINE>
[2 rows x 2 columns]
Parameters
Name Description
numeric_only bool, default False

Include only float, int, boolean columns.
exact bool, default True

Calculate the exact median instead of an approximation.
Returns
Type Description
bigframes.pandas.DataFrame or bigframes.pandas.Series Median of groups.

min

min(*args) -> bigframes.series.Series

Compute min of group values.

Examples:

For SeriesGroupBy:

>>> import bigframes.pandas as bpd
>>> import numpy as np
>>> bpd.options.display.progress_bar = None

>>> lst = ['a', 'a', 'b', 'b']
>>> ser = bpd.Series([1, 2, 3, 4], index=lst)
>>> ser.groupby(level=0).min()
a     1
b     3
dtype: Int64

For DataFrameGroupBy:

>>> data = [[1, 8, 2], [1, 2, 5], [2, 5, 8], [2, 6, 9]]
>>> df = bpd.DataFrame(data, columns=["a", "b", "c"],
...                    index=["tiger", "leopard", "cheetah", "lion"])
>>> df.groupby(by=["a"]).min()
   b  c
a
1  2  2
2  5  8
<BLANKLINE>
[2 rows x 2 columns]
Parameters
Name Description
numeric_only bool, default False

Include only float, int, boolean columns.
min_count int, default 0

The required number of valid values to perform the operation. If fewer than min_count and non-NA values are present, the result will be NA.
Returns
Type Description
bigframes.pandas.DataFrame or bigframes.pandas.Series Computed min of values within each group.

nunique

nunique() -> bigframes.series.Series

Return number of unique elements in the group.

Examples:

>>> import bigframes.pandas as bpd
>>> import numpy as np
>>> bpd.options.display.progress_bar = None

>>> lst = ['a', 'a', 'b', 'b']
>>> ser = bpd.Series([1, 2, 3, 3], index=lst)
>>> ser.groupby(level=0).nunique()
a    2
b    1
dtype: Int64
Returns
Type Description
bigframes.pandas.Series Number of unique values within each group.

prod

prod(*args) -> bigframes.series.Series

Compute prod of group values. (DataFrameGroupBy functionality is not yet available.)

Examples:

For SeriesGroupBy:

>>> import bigframes.pandas as bpd
>>> import numpy as np
>>> bpd.options.display.progress_bar = None

>>> lst = ['a', 'a', 'b', 'b']
>>> ser = bpd.Series([1, 2, 3, 4], index=lst)
>>> ser.groupby(level=0).prod()
a     2.0
b    12.0
dtype: Float64
Parameters
Name Description
numeric_only bool, default False

Include only float, int, boolean columns.
min_count int, default 0

The required number of valid values to perform the operation. If fewer than min_count and non-NA values are present, the result will be NA.
Returns
Type Description
bigframes.pandas.DataFrame or bigframes.pandas.Series Computed prod of values within each group.

quantile

quantile(
    q: typing.Union[float, typing.Sequence[float]] = 0.5, *, numeric_only: bool = False
) -> bigframes.series.Series

Return group values at the given quantile, a la numpy.percentile.

Examples:

>>> import bigframes.pandas as bpd
>>> bpd.options.display.progress_bar = None
>>> df = bpd.DataFrame([
...     ['a', 1], ['a', 2], ['a', 3],
...     ['b', 1], ['b', 3], ['b', 5]
... ], columns=['key', 'val'])
>>> df.groupby('key').quantile()
     val
key
a    2.0
b    3.0
<BLANKLINE>
[2 rows x 1 columns]
Parameters
Name Description
q float or array-like, default 0.5 (50% quantile)

Value(s) between 0 and 1 providing the quantile(s) to compute.
numeric_only bool, default False

Include only float, int or boolean data.
Returns
Type Description
bigframes.pandas.DataFrame or bigframes.pandas.Series Return type determined by caller of GroupBy object.

rank

rank(
    method="average", ascending: bool = True, na_option: str = "keep"
) -> bigframes.series.Series

Provide the rank of values within each group.

Examples:

>>> import bigframes.pandas as bpd
>>> import numpy as np
>>> bpd.options.display.progress_bar = None

>>> df = bpd.DataFrame(
...     {
...         "group": ["a", "a", "a", "a", "a", "b", "b", "b", "b", "b"],
...         "value": [2, 4, 2, 3, 5, 1, 2, 4, 1, 5],
...     }
... )
>>> df
group  value
0     a      2
1     a      4
2     a      2
3     a      3
4     a      5
5     b      1
6     b      2
7     b      4
8     b      1
9     b      5
<BLANKLINE>
[10 rows x 2 columns]
>>> for method in ['average', 'min', 'max', 'dense', 'first']:
...     df[f'{method}_rank'] = df.groupby('group')['value'].rank(method)
>>> df
group  value  average_rank  min_rank  max_rank  dense_rank  first_rank
0     a      2           1.5       1.0       2.0         1.0         1.0
1     a      4           4.0       4.0       4.0         3.0         4.0
2     a      2           1.5       1.0       2.0         1.0         2.0
3     a      3           3.0       3.0       3.0         2.0         3.0
4     a      5           5.0       5.0       5.0         4.0         5.0
5     b      1           1.5       1.0       2.0         1.0         1.0
6     b      2           3.0       3.0       3.0         2.0         3.0
7     b      4           4.0       4.0       4.0         3.0         4.0
8     b      1           1.5       1.0       2.0         1.0         2.0
9     b      5           5.0       5.0       5.0         4.0         5.0
<BLANKLINE>
[10 rows x 7 columns]
Parameters
Name Description
method {'average', 'min', 'max', 'first', 'dense'}, default 'average'
  • average: average rank of group. * min: lowest rank in group. * max: highest rank in group. * first: ranks assigned in order they appear in the array. * dense: like 'min', but rank always increases by 1 between groups.
ascending bool, default True

False for ranks by high (1) to low (N).
na_option {'keep', 'top', 'bottom'}, default 'keep'
  • keep: leave NA values where they are. * top: smallest rank if ascending. * bottom: smallest rank if descending.

rolling

rolling(
    window: (
        int
        | pandas._libs.tslibs.timedeltas.Timedelta
        | numpy.timedelta64
        | datetime.timedelta
        | str
    ),
    min_periods=None,
    closed: typing.Literal["right", "left", "both", "neither"] = "right",
) -> bigframes.core.window.rolling.Window

Returns a rolling grouper, providing rolling functionality per group.

Examples:

>>> import bigframes.pandas as bpd
>>> import numpy as np
>>> bpd.options.display.progress_bar = None

>>> lst = ['a', 'a', 'a', 'a', 'e']
>>> ser = bpd.Series([1, 0, -2, -1, 2], index=lst)
>>> ser.groupby(level=0).rolling(2).min()
index  index
a      a        <NA>
    a           0
    a          -2
    a          -2
e      e        <NA>
dtype: Int64
Parameters
Name Description
window int, pandas.Timedelta, numpy.timedelta64, datetime.timedelta, str

Size of the moving window. If an integer, the fixed number of observations used for each window. If a string, the timedelta representation in string. This string must be parsable by pandas.Timedelta(). Otherwise, the time range for each window.
min_periods int, default None

Minimum number of observations in window required to have a value; otherwise, result is np.nan. For a window that is specified by an integer, min_periods will default to the size of the window. For a window that is not spicified by an interger, min_periods will default to 1.
on str, optional

For a DataFrame, a column label on which to calculate the rolling window, rather than the DataFrame’s index.
closed str, default 'right'

If 'right', the first point in the window is excluded from calculations. If 'left', the last point in the window is excluded from calculations. If 'both', the no points in the window are excluded from calculations. If 'neither', the first and last points in the window are excluded from calculations.
Returns
Type Description
bigframes.pandas.DataFrame or bigframes.pandas.Series Return a new grouper with our rolling appended.

shift

shift(periods=1) -> bigframes.series.Series

Shift index by desired number of periods.

size

size() -> bigframes.series.Series

Compute group sizes.

Examples:

For SeriesGroupBy:

>>> import bigframes.pandas as bpd
>>> bpd.options.display.progress_bar = None

>>> lst = ['a', 'a', 'b']
>>> ser = bpd.Series([1, 2, 3], index=lst)
>>> ser
a     1
a     2
b     3
dtype: Int64
>>> ser.groupby(level=0).size()
a    2
b    1
dtype: Int64

For DataFrameGroupBy:

>>> data = [[1, 2, 3], [1, 5, 6], [7, 8, 9]]
>>> df = bpd.DataFrame(data, columns=["a", "b", "c"],
...                   index=["owl", "toucan", "eagle"])
>>> df
        a  b  c
owl     1  2  3
toucan  1  5  6
eagle   7  8  9
[3 rows x 3 columns]
>>> df.groupby("a").size()
a
1    2
7    1
dtype: Int64
Returns
Type Description
bigframes.pandas.DataFrame or bigframes.pandas.Series Number of rows in each group as a Series if as_index is True or a DataFrame if as_index is False.

skew

skew(*args, **kwargs) -> bigframes.series.Series

Return unbiased skew within groups.

Normalized by N-1.

Examples:

For SeriesGroupBy:

>>> import bigframes.pandas as bpd
>>> import numpy as np
>>> bpd.options.display.progress_bar = None

>>> ser = bpd.Series([390., 350., 357., np.nan, 22., 20., 30.],
...                  index=['Falcon', 'Falcon', 'Falcon', 'Falcon',
...                         'Parrot', 'Parrot', 'Parrot'],
...                  name="Max Speed")
>>> ser.groupby(level=0).skew()
Falcon    1.525174
Parrot    1.457863
Name: Max Speed, dtype: Float64
Parameter
Name Description
numeric_only bool, default False

Include only float, int or boolean data.
Returns
Type Description
bigframes.pandas.DataFrame or bigframes.pandas.Series Variance of values within each group.

std

std(*args, **kwargs) -> bigframes.series.Series

Compute standard deviation of groups, excluding missing values.

For multiple groupings, the result index will be a MultiIndex.

Examples:

For SeriesGroupBy:

>>> import bigframes.pandas as bpd
>>> import numpy as np
>>> bpd.options.display.progress_bar = None

>>> lst = ['a', 'a', 'a', 'b', 'b', 'b']
>>> ser = bpd.Series([7, 2, 8, 4, 3, 3], index=lst)
>>> ser.groupby(level=0).std()
a     3.21455
b     0.57735
dtype: Float64

For DataFrameGroupBy:

>>> data = {'a': [1, 3, 5, 7, 7, 8, 3], 'b': [1, 4, 8, 4, 4, 2, 1]}
>>> df = bpd.DataFrame(data, index=['dog', 'dog', 'dog',
...                    'mouse', 'mouse', 'mouse', 'mouse'])
>>> df.groupby(level=0).std()
              a         b
dog         2.0  3.511885
mouse  2.217356       1.5
<BLANKLINE>
[2 rows x 2 columns]
Parameter
Name Description
numeric_only bool, default False

Include only float, int or boolean data.
Returns
Type Description
bigframes.pandas.DataFrame or bigframes.pandas.Series Standard deviation of values within each group.

sum

sum(*args) -> bigframes.series.Series

Compute sum of group values.

Examples:

For SeriesGroupBy:

>>> import bigframes.pandas as bpd
>>> bpd.options.display.progress_bar = None

>>> lst = ['a', 'a', 'b', 'b']
>>> ser = bpd.Series([1, 2, 3, 4], index=lst)
>>> ser.groupby(level=0).sum()
a     3
b     7
dtype: Int64

For DataFrameGroupBy:

>>> data = [[1, 8, 2], [1, 2, 5], [2, 5, 8], [2, 6, 9]]
>>> df = bpd.DataFrame(data, columns=["a", "b", "c"],
...                   index=["tiger", "leopard", "cheetah", "lion"])
>>> df.groupby("a").sum()
    b   c
a
1  10   7
2  11  17
<BLANKLINE>
[2 rows x 2 columns]
Parameters
Name Description
numeric_only bool, default False

Include only float, int, boolean columns.
min_count int, default 0

The required number of valid values to perform the operation. If fewer than min_count and non-NA values are present, the result will be NA.
Returns
Type Description
bigframes.pandas.DataFrame or bigframes.pandas.Series Computed sum of values within each group.

var

var(*args, **kwargs) -> bigframes.series.Series

Compute variance of groups, excluding missing values.

For multiple groupings, the result index will be a MultiIndex.

Examples:

For SeriesGroupBy:

>>> import bigframes.pandas as bpd
>>> import numpy as np
>>> bpd.options.display.progress_bar = None

>>> lst = ['a', 'a', 'a', 'b', 'b', 'b']
>>> ser = bpd.Series([7, 2, 8, 4, 3, 3], index=lst)
>>> ser.groupby(level=0).var()
a   10.333333
b    0.333333
dtype: Float64

For DataFrameGroupBy:

>>> data = {'a': [1, 3, 5, 7, 7, 8, 3], 'b': [1, 4, 8, 4, 4, 2, 1]}
>>> df = bpd.DataFrame(data, index=['dog', 'dog', 'dog',
...                    'mouse', 'mouse', 'mouse', 'mouse'])
>>> df.groupby(level=0).var()
              a          b
dog         4.0  12.333333
mouse  4.916667       2.25
<BLANKLINE>
[2 rows x 2 columns]
Parameter
Name Description
numeric_only bool, default False

Include only float, int or boolean data.
Returns
Type Description
bigframes.pandas.DataFrame or bigframes.pandas.Series Variance of values within each group.