Unexpected TypeError using pd.NamedAgg dict with pd.rolling · Issue #28333 · pandas-dev/pandas (original) (raw)

Code Sample

import pandas as pd animals = pd.DataFrame({'kind': ['cat', 'dog', 'cat', 'dog'], 'height': [9.1, 6.0, 9.5, 34.0], 'weight': [7.9, 7.5, 9.9, 198.0]})

(1) - doesn't work

animals.groupby("kind").rolling(1).agg(**{'total weight': pd.NamedAgg(column='weight', aggfunc=sum), 'min_weight': pd.NamedAgg(column='weight', aggfunc=min)})

(2) - works

animals.groupby("kind").agg(**{'total weight': pd.NamedAgg(column='weight', aggfunc=sum), 'min_weight': pd.NamedAgg(column='weight', aggfunc=min)})

works, but returns multiindex

animals.groupby("kind").rolling(1).agg({'weight': {'total_weight': 'sum', 'min_weight': 'min'}})

(3) - this is what I'd want, expected output of (1)

animals.groupby("kind").rolling(1).agg({'weight': {'total_weight': 'sum', 'min_weight': 'min'}}).droplevel(0, axis=1)

Problem description

Pandas version 0.25 provides new aggregate functionality through NamedAgg. I would expect to be able to pass this in after a groupby as a pd.apply statement, and also after a groupby and pd.rolling.

However, when I try to pass in a dict of NamedAgg tuples as shown in (1) in the example code I get the following TypeError: TypeError: aggregate() missing 1 required positional argument: 'arg'

Is this expected or am I incorrectly using this functionality? Thanks in advance!

Output of pd.show_versions()

INSTALLED VERSIONS

commit : None
python : 3.7.4.final.0
python-bits : 64
OS : Darwin
OS-release : 18.7.0
machine : x86_64
processor : i386
byteorder : little
LC_ALL : None
LANG : None
LOCALE : en_US.UTF-8
pandas : 0.25.1
numpy : 1.16.1
pytz : 2018.5
dateutil : 2.7.3
pip : 19.1.1
setuptools : 41.0.1
Cython : None
pytest : 4.3.1
hypothesis : None
sphinx : 1.8.5
blosc : None
feather : None
xlsxwriter : None
lxml.etree : None
html5lib : None
pymysql : 0.9.2
psycopg2 : 2.7.7 (dt dec pq3 ext lo64)
jinja2 : 2.10.1
IPython : 7.3.0
pandas_datareader: None
bs4 : 4.7.1
bottleneck : None
fastparquet : None
gcsfs : None
lxml.etree : None
matplotlib : 3.0.3
numexpr : None
odfpy : None
openpyxl : 2.6.1
pandas_gbq : None
pyarrow : None
pytables : None
s3fs : None
scipy : 1.1.0
sqlalchemy : 1.3.3
tables : None
xarray : None
xlrd : 1.2.0
xlwt : None
xlsxwriter : None