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test_filters.py
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test_filters.py
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# -*- coding: utf-8 -*-
from __future__ import print_function
import pytest
import numpy as np
import pandas.util.testing as tm
from pandas import Timestamp, DataFrame, Series
import pandas as pd
def test_filter_series():
s = pd.Series([1, 3, 20, 5, 22, 24, 7])
expected_odd = pd.Series([1, 3, 5, 7], index=[0, 1, 3, 6])
expected_even = pd.Series([20, 22, 24], index=[2, 4, 5])
grouper = s.apply(lambda x: x % 2)
grouped = s.groupby(grouper)
tm.assert_series_equal(
grouped.filter(lambda x: x.mean() < 10), expected_odd)
tm.assert_series_equal(
grouped.filter(lambda x: x.mean() > 10), expected_even)
# Test dropna=False.
tm.assert_series_equal(
grouped.filter(lambda x: x.mean() < 10, dropna=False),
expected_odd.reindex(s.index))
tm.assert_series_equal(
grouped.filter(lambda x: x.mean() > 10, dropna=False),
expected_even.reindex(s.index))
def test_filter_single_column_df():
df = pd.DataFrame([1, 3, 20, 5, 22, 24, 7])
expected_odd = pd.DataFrame([1, 3, 5, 7], index=[0, 1, 3, 6])
expected_even = pd.DataFrame([20, 22, 24], index=[2, 4, 5])
grouper = df[0].apply(lambda x: x % 2)
grouped = df.groupby(grouper)
tm.assert_frame_equal(
grouped.filter(lambda x: x.mean() < 10), expected_odd)
tm.assert_frame_equal(
grouped.filter(lambda x: x.mean() > 10), expected_even)
# Test dropna=False.
tm.assert_frame_equal(
grouped.filter(lambda x: x.mean() < 10, dropna=False),
expected_odd.reindex(df.index))
tm.assert_frame_equal(
grouped.filter(lambda x: x.mean() > 10, dropna=False),
expected_even.reindex(df.index))
def test_filter_multi_column_df():
df = pd.DataFrame({'A': [1, 12, 12, 1], 'B': [1, 1, 1, 1]})
grouper = df['A'].apply(lambda x: x % 2)
grouped = df.groupby(grouper)
expected = pd.DataFrame({'A': [12, 12], 'B': [1, 1]}, index=[1, 2])
tm.assert_frame_equal(
grouped.filter(lambda x: x['A'].sum() - x['B'].sum() > 10),
expected)
def test_filter_mixed_df():
df = pd.DataFrame({'A': [1, 12, 12, 1], 'B': 'a b c d'.split()})
grouper = df['A'].apply(lambda x: x % 2)
grouped = df.groupby(grouper)
expected = pd.DataFrame({'A': [12, 12], 'B': ['b', 'c']}, index=[1, 2])
tm.assert_frame_equal(
grouped.filter(lambda x: x['A'].sum() > 10), expected)
def test_filter_out_all_groups():
s = pd.Series([1, 3, 20, 5, 22, 24, 7])
grouper = s.apply(lambda x: x % 2)
grouped = s.groupby(grouper)
tm.assert_series_equal(grouped.filter(lambda x: x.mean() > 1000), s[[]])
df = pd.DataFrame({'A': [1, 12, 12, 1], 'B': 'a b c d'.split()})
grouper = df['A'].apply(lambda x: x % 2)
grouped = df.groupby(grouper)
tm.assert_frame_equal(
grouped.filter(lambda x: x['A'].sum() > 1000), df.loc[[]])
def test_filter_out_no_groups():
s = pd.Series([1, 3, 20, 5, 22, 24, 7])
grouper = s.apply(lambda x: x % 2)
grouped = s.groupby(grouper)
filtered = grouped.filter(lambda x: x.mean() > 0)
tm.assert_series_equal(filtered, s)
df = pd.DataFrame({'A': [1, 12, 12, 1], 'B': 'a b c d'.split()})
grouper = df['A'].apply(lambda x: x % 2)
grouped = df.groupby(grouper)
filtered = grouped.filter(lambda x: x['A'].mean() > 0)
tm.assert_frame_equal(filtered, df)
def test_filter_out_all_groups_in_df():
# GH12768
df = pd.DataFrame({'a': [1, 1, 2], 'b': [1, 2, 0]})
res = df.groupby('a')
res = res.filter(lambda x: x['b'].sum() > 5, dropna=False)
expected = pd.DataFrame({'a': [np.nan] * 3, 'b': [np.nan] * 3})
tm.assert_frame_equal(expected, res)
df = pd.DataFrame({'a': [1, 1, 2], 'b': [1, 2, 0]})
res = df.groupby('a')
res = res.filter(lambda x: x['b'].sum() > 5, dropna=True)
expected = pd.DataFrame({'a': [], 'b': []}, dtype="int64")
tm.assert_frame_equal(expected, res)
def test_filter_condition_raises():
def raise_if_sum_is_zero(x):
if x.sum() == 0:
raise ValueError
else:
return x.sum() > 0
s = pd.Series([-1, 0, 1, 2])
grouper = s.apply(lambda x: x % 2)
grouped = s.groupby(grouper)
pytest.raises(TypeError,
lambda: grouped.filter(raise_if_sum_is_zero))
def test_filter_with_axis_in_groupby():
# issue 11041
index = pd.MultiIndex.from_product([range(10), [0, 1]])
data = pd.DataFrame(
np.arange(100).reshape(-1, 20), columns=index, dtype='int64')
result = data.groupby(level=0,
axis=1).filter(lambda x: x.iloc[0, 0] > 10)
expected = data.iloc[:, 12:20]
tm.assert_frame_equal(result, expected)
def test_filter_bad_shapes():
df = DataFrame({'A': np.arange(8),
'B': list('aabbbbcc'),
'C': np.arange(8)})
s = df['B']
g_df = df.groupby('B')
g_s = s.groupby(s)
f = lambda x: x
pytest.raises(TypeError, lambda: g_df.filter(f))
pytest.raises(TypeError, lambda: g_s.filter(f))
f = lambda x: x == 1
pytest.raises(TypeError, lambda: g_df.filter(f))
pytest.raises(TypeError, lambda: g_s.filter(f))
f = lambda x: np.outer(x, x)
pytest.raises(TypeError, lambda: g_df.filter(f))
pytest.raises(TypeError, lambda: g_s.filter(f))
def test_filter_nan_is_false():
df = DataFrame({'A': np.arange(8),
'B': list('aabbbbcc'),
'C': np.arange(8)})
s = df['B']
g_df = df.groupby(df['B'])
g_s = s.groupby(s)
f = lambda x: np.nan
tm.assert_frame_equal(g_df.filter(f), df.loc[[]])
tm.assert_series_equal(g_s.filter(f), s[[]])
def test_filter_against_workaround():
np.random.seed(0)
# Series of ints
s = Series(np.random.randint(0, 100, 1000))
grouper = s.apply(lambda x: np.round(x, -1))
grouped = s.groupby(grouper)
f = lambda x: x.mean() > 10
old_way = s[grouped.transform(f).astype('bool')]
new_way = grouped.filter(f)
tm.assert_series_equal(new_way.sort_values(), old_way.sort_values())
# Series of floats
s = 100 * Series(np.random.random(1000))
grouper = s.apply(lambda x: np.round(x, -1))
grouped = s.groupby(grouper)
f = lambda x: x.mean() > 10
old_way = s[grouped.transform(f).astype('bool')]
new_way = grouped.filter(f)
tm.assert_series_equal(new_way.sort_values(), old_way.sort_values())
# Set up DataFrame of ints, floats, strings.
from string import ascii_lowercase
letters = np.array(list(ascii_lowercase))
N = 1000
random_letters = letters.take(np.random.randint(0, 26, N))
df = DataFrame({'ints': Series(np.random.randint(0, 100, N)),
'floats': N / 10 * Series(np.random.random(N)),
'letters': Series(random_letters)})
# Group by ints; filter on floats.
grouped = df.groupby('ints')
old_way = df[grouped.floats.
transform(lambda x: x.mean() > N / 20).astype('bool')]
new_way = grouped.filter(lambda x: x['floats'].mean() > N / 20)
tm.assert_frame_equal(new_way, old_way)
# Group by floats (rounded); filter on strings.
grouper = df.floats.apply(lambda x: np.round(x, -1))
grouped = df.groupby(grouper)
old_way = df[grouped.letters.
transform(lambda x: len(x) < N / 10).astype('bool')]
new_way = grouped.filter(lambda x: len(x.letters) < N / 10)
tm.assert_frame_equal(new_way, old_way)
# Group by strings; filter on ints.
grouped = df.groupby('letters')
old_way = df[grouped.ints.
transform(lambda x: x.mean() > N / 20).astype('bool')]
new_way = grouped.filter(lambda x: x['ints'].mean() > N / 20)
tm.assert_frame_equal(new_way, old_way)
def test_filter_using_len():
# BUG GH4447
df = DataFrame({'A': np.arange(8),
'B': list('aabbbbcc'),
'C': np.arange(8)})
grouped = df.groupby('B')
actual = grouped.filter(lambda x: len(x) > 2)
expected = DataFrame(
{'A': np.arange(2, 6),
'B': list('bbbb'),
'C': np.arange(2, 6)}, index=np.arange(2, 6))
tm.assert_frame_equal(actual, expected)
actual = grouped.filter(lambda x: len(x) > 4)
expected = df.loc[[]]
tm.assert_frame_equal(actual, expected)
# Series have always worked properly, but we'll test anyway.
s = df['B']
grouped = s.groupby(s)
actual = grouped.filter(lambda x: len(x) > 2)
expected = Series(4 * ['b'], index=np.arange(2, 6), name='B')
tm.assert_series_equal(actual, expected)
actual = grouped.filter(lambda x: len(x) > 4)
expected = s[[]]
tm.assert_series_equal(actual, expected)
def test_filter_maintains_ordering():
# Simple case: index is sequential. #4621
df = DataFrame({'pid': [1, 1, 1, 2, 2, 3, 3, 3],
'tag': [23, 45, 62, 24, 45, 34, 25, 62]})
s = df['pid']
grouped = df.groupby('tag')
actual = grouped.filter(lambda x: len(x) > 1)
expected = df.iloc[[1, 2, 4, 7]]
tm.assert_frame_equal(actual, expected)
grouped = s.groupby(df['tag'])
actual = grouped.filter(lambda x: len(x) > 1)
expected = s.iloc[[1, 2, 4, 7]]
tm.assert_series_equal(actual, expected)
# Now index is sequentially decreasing.
df.index = np.arange(len(df) - 1, -1, -1)
s = df['pid']
grouped = df.groupby('tag')
actual = grouped.filter(lambda x: len(x) > 1)
expected = df.iloc[[1, 2, 4, 7]]
tm.assert_frame_equal(actual, expected)
grouped = s.groupby(df['tag'])
actual = grouped.filter(lambda x: len(x) > 1)
expected = s.iloc[[1, 2, 4, 7]]
tm.assert_series_equal(actual, expected)
# Index is shuffled.
SHUFFLED = [4, 6, 7, 2, 1, 0, 5, 3]
df.index = df.index[SHUFFLED]
s = df['pid']
grouped = df.groupby('tag')
actual = grouped.filter(lambda x: len(x) > 1)
expected = df.iloc[[1, 2, 4, 7]]
tm.assert_frame_equal(actual, expected)
grouped = s.groupby(df['tag'])
actual = grouped.filter(lambda x: len(x) > 1)
expected = s.iloc[[1, 2, 4, 7]]
tm.assert_series_equal(actual, expected)
def test_filter_multiple_timestamp():
# GH 10114
df = DataFrame({'A': np.arange(5, dtype='int64'),
'B': ['foo', 'bar', 'foo', 'bar', 'bar'],
'C': Timestamp('20130101')})
grouped = df.groupby(['B', 'C'])
result = grouped['A'].filter(lambda x: True)
tm.assert_series_equal(df['A'], result)
result = grouped['A'].transform(len)
expected = Series([2, 3, 2, 3, 3], name='A')
tm.assert_series_equal(result, expected)
result = grouped.filter(lambda x: True)
tm.assert_frame_equal(df, result)
result = grouped.transform('sum')
expected = DataFrame({'A': [2, 8, 2, 8, 8]})
tm.assert_frame_equal(result, expected)
result = grouped.transform(len)
expected = DataFrame({'A': [2, 3, 2, 3, 3]})
tm.assert_frame_equal(result, expected)
def test_filter_and_transform_with_non_unique_int_index():
# GH4620
index = [1, 1, 1, 2, 1, 1, 0, 1]
df = DataFrame({'pid': [1, 1, 1, 2, 2, 3, 3, 3],
'tag': [23, 45, 62, 24, 45, 34, 25, 62]}, index=index)
grouped_df = df.groupby('tag')
ser = df['pid']
grouped_ser = ser.groupby(df['tag'])
expected_indexes = [1, 2, 4, 7]
# Filter DataFrame
actual = grouped_df.filter(lambda x: len(x) > 1)
expected = df.iloc[expected_indexes]
tm.assert_frame_equal(actual, expected)
actual = grouped_df.filter(lambda x: len(x) > 1, dropna=False)
expected = df.copy()
expected.iloc[[0, 3, 5, 6]] = np.nan
tm.assert_frame_equal(actual, expected)
# Filter Series
actual = grouped_ser.filter(lambda x: len(x) > 1)
expected = ser.take(expected_indexes)
tm.assert_series_equal(actual, expected)
actual = grouped_ser.filter(lambda x: len(x) > 1, dropna=False)
NA = np.nan
expected = Series([NA, 1, 1, NA, 2, NA, NA, 3], index, name='pid')
# ^ made manually because this can get confusing!
tm.assert_series_equal(actual, expected)
# Transform Series
actual = grouped_ser.transform(len)
expected = Series([1, 2, 2, 1, 2, 1, 1, 2], index, name='pid')
tm.assert_series_equal(actual, expected)
# Transform (a column from) DataFrameGroupBy
actual = grouped_df.pid.transform(len)
tm.assert_series_equal(actual, expected)
def test_filter_and_transform_with_multiple_non_unique_int_index():
# GH4620
index = [1, 1, 1, 2, 0, 0, 0, 1]
df = DataFrame({'pid': [1, 1, 1, 2, 2, 3, 3, 3],
'tag': [23, 45, 62, 24, 45, 34, 25, 62]}, index=index)
grouped_df = df.groupby('tag')
ser = df['pid']
grouped_ser = ser.groupby(df['tag'])
expected_indexes = [1, 2, 4, 7]
# Filter DataFrame
actual = grouped_df.filter(lambda x: len(x) > 1)
expected = df.iloc[expected_indexes]
tm.assert_frame_equal(actual, expected)
actual = grouped_df.filter(lambda x: len(x) > 1, dropna=False)
expected = df.copy()
expected.iloc[[0, 3, 5, 6]] = np.nan
tm.assert_frame_equal(actual, expected)
# Filter Series
actual = grouped_ser.filter(lambda x: len(x) > 1)
expected = ser.take(expected_indexes)
tm.assert_series_equal(actual, expected)
actual = grouped_ser.filter(lambda x: len(x) > 1, dropna=False)
NA = np.nan
expected = Series([NA, 1, 1, NA, 2, NA, NA, 3], index, name='pid')
# ^ made manually because this can get confusing!
tm.assert_series_equal(actual, expected)
# Transform Series
actual = grouped_ser.transform(len)
expected = Series([1, 2, 2, 1, 2, 1, 1, 2], index, name='pid')
tm.assert_series_equal(actual, expected)
# Transform (a column from) DataFrameGroupBy
actual = grouped_df.pid.transform(len)
tm.assert_series_equal(actual, expected)
def test_filter_and_transform_with_non_unique_float_index():
# GH4620
index = np.array([1, 1, 1, 2, 1, 1, 0, 1], dtype=float)
df = DataFrame({'pid': [1, 1, 1, 2, 2, 3, 3, 3],
'tag': [23, 45, 62, 24, 45, 34, 25, 62]}, index=index)
grouped_df = df.groupby('tag')
ser = df['pid']
grouped_ser = ser.groupby(df['tag'])
expected_indexes = [1, 2, 4, 7]
# Filter DataFrame
actual = grouped_df.filter(lambda x: len(x) > 1)
expected = df.iloc[expected_indexes]
tm.assert_frame_equal(actual, expected)
actual = grouped_df.filter(lambda x: len(x) > 1, dropna=False)
expected = df.copy()
expected.iloc[[0, 3, 5, 6]] = np.nan
tm.assert_frame_equal(actual, expected)
# Filter Series
actual = grouped_ser.filter(lambda x: len(x) > 1)
expected = ser.take(expected_indexes)
tm.assert_series_equal(actual, expected)
actual = grouped_ser.filter(lambda x: len(x) > 1, dropna=False)
NA = np.nan
expected = Series([NA, 1, 1, NA, 2, NA, NA, 3], index, name='pid')
# ^ made manually because this can get confusing!
tm.assert_series_equal(actual, expected)
# Transform Series
actual = grouped_ser.transform(len)
expected = Series([1, 2, 2, 1, 2, 1, 1, 2], index, name='pid')
tm.assert_series_equal(actual, expected)
# Transform (a column from) DataFrameGroupBy
actual = grouped_df.pid.transform(len)
tm.assert_series_equal(actual, expected)
def test_filter_and_transform_with_non_unique_timestamp_index():
# GH4620
t0 = Timestamp('2013-09-30 00:05:00')
t1 = Timestamp('2013-10-30 00:05:00')
t2 = Timestamp('2013-11-30 00:05:00')
index = [t1, t1, t1, t2, t1, t1, t0, t1]
df = DataFrame({'pid': [1, 1, 1, 2, 2, 3, 3, 3],
'tag': [23, 45, 62, 24, 45, 34, 25, 62]}, index=index)
grouped_df = df.groupby('tag')
ser = df['pid']
grouped_ser = ser.groupby(df['tag'])
expected_indexes = [1, 2, 4, 7]
# Filter DataFrame
actual = grouped_df.filter(lambda x: len(x) > 1)
expected = df.iloc[expected_indexes]
tm.assert_frame_equal(actual, expected)
actual = grouped_df.filter(lambda x: len(x) > 1, dropna=False)
expected = df.copy()
expected.iloc[[0, 3, 5, 6]] = np.nan
tm.assert_frame_equal(actual, expected)
# Filter Series
actual = grouped_ser.filter(lambda x: len(x) > 1)
expected = ser.take(expected_indexes)
tm.assert_series_equal(actual, expected)
actual = grouped_ser.filter(lambda x: len(x) > 1, dropna=False)
NA = np.nan
expected = Series([NA, 1, 1, NA, 2, NA, NA, 3], index, name='pid')
# ^ made manually because this can get confusing!
tm.assert_series_equal(actual, expected)
# Transform Series
actual = grouped_ser.transform(len)
expected = Series([1, 2, 2, 1, 2, 1, 1, 2], index, name='pid')
tm.assert_series_equal(actual, expected)
# Transform (a column from) DataFrameGroupBy
actual = grouped_df.pid.transform(len)
tm.assert_series_equal(actual, expected)
def test_filter_and_transform_with_non_unique_string_index():
# GH4620
index = list('bbbcbbab')
df = DataFrame({'pid': [1, 1, 1, 2, 2, 3, 3, 3],
'tag': [23, 45, 62, 24, 45, 34, 25, 62]}, index=index)
grouped_df = df.groupby('tag')
ser = df['pid']
grouped_ser = ser.groupby(df['tag'])
expected_indexes = [1, 2, 4, 7]
# Filter DataFrame
actual = grouped_df.filter(lambda x: len(x) > 1)
expected = df.iloc[expected_indexes]
tm.assert_frame_equal(actual, expected)
actual = grouped_df.filter(lambda x: len(x) > 1, dropna=False)
expected = df.copy()
expected.iloc[[0, 3, 5, 6]] = np.nan
tm.assert_frame_equal(actual, expected)
# Filter Series
actual = grouped_ser.filter(lambda x: len(x) > 1)
expected = ser.take(expected_indexes)
tm.assert_series_equal(actual, expected)
actual = grouped_ser.filter(lambda x: len(x) > 1, dropna=False)
NA = np.nan
expected = Series([NA, 1, 1, NA, 2, NA, NA, 3], index, name='pid')
# ^ made manually because this can get confusing!
tm.assert_series_equal(actual, expected)
# Transform Series
actual = grouped_ser.transform(len)
expected = Series([1, 2, 2, 1, 2, 1, 1, 2], index, name='pid')
tm.assert_series_equal(actual, expected)
# Transform (a column from) DataFrameGroupBy
actual = grouped_df.pid.transform(len)
tm.assert_series_equal(actual, expected)
def test_filter_has_access_to_grouped_cols():
df = DataFrame([[1, 2], [1, 3], [5, 6]], columns=['A', 'B'])
g = df.groupby('A')
# previously didn't have access to col A #????
filt = g.filter(lambda x: x['A'].sum() == 2)
tm.assert_frame_equal(filt, df.iloc[[0, 1]])
def test_filter_enforces_scalarness():
df = pd.DataFrame([
['best', 'a', 'x'],
['worst', 'b', 'y'],
['best', 'c', 'x'],
['best', 'd', 'y'],
['worst', 'd', 'y'],
['worst', 'd', 'y'],
['best', 'd', 'z'],
], columns=['a', 'b', 'c'])
with tm.assert_raises_regex(TypeError,
'filter function returned a.*'):
df.groupby('c').filter(lambda g: g['a'] == 'best')
def test_filter_non_bool_raises():
df = pd.DataFrame([
['best', 'a', 1],
['worst', 'b', 1],
['best', 'c', 1],
['best', 'd', 1],
['worst', 'd', 1],
['worst', 'd', 1],
['best', 'd', 1],
], columns=['a', 'b', 'c'])
with tm.assert_raises_regex(TypeError,
'filter function returned a.*'):
df.groupby('a').filter(lambda g: g.c.mean())
def test_filter_dropna_with_empty_groups():
# GH 10780
data = pd.Series(np.random.rand(9), index=np.repeat([1, 2, 3], 3))
groupped = data.groupby(level=0)
result_false = groupped.filter(lambda x: x.mean() > 1, dropna=False)
expected_false = pd.Series([np.nan] * 9,
index=np.repeat([1, 2, 3], 3))
tm.assert_series_equal(result_false, expected_false)
result_true = groupped.filter(lambda x: x.mean() > 1, dropna=True)
expected_true = pd.Series(index=pd.Index([], dtype=int))
tm.assert_series_equal(result_true, expected_true)