pandas: complex filter on rows of DataFrame

Question

I would like to filter rows by a function of each row, e.g.

def f(row):
  return sin(row[\'velocity\'])/np.prod([\'masses\']) > 5

df = pandas.DataFrame(.         


        

Answer 1

Specify reduce=True to handle empty DataFrames as well.

import pandas as pd

t = pd.DataFrame(columns=['a', 'b'])
t[t.apply(lambda x: x['a'] > 1, axis=1, reduce=True)]

https://crosscompute.com/n/jAbsB6OIm6oCCJX9PBIbY5FECFKCClyV/-/apply-custom-filter-on-rows-of-dataframe