A quick pandas function to return the cross product of two data frames, kind of emulating tidyr::crossing function.

crossing.py

import pandas as pd
from functools import reduce

def crossing(df1: pd.DataFrame, df2: pd.DataFrame) -> pd.DataFrame:
    """
    Returns a data frame with the cross product (every pair possible) of rows
    between df1 and df2
    """
    df1["join_key"] = 0
    df2["join_key"] = 0
    rdf = df1.merge(df2, how="outer", on="join_key").drop(columns=["join_key"])
    df1.drop(columns=["join_key"], inplace=True)
    df2.drop(columns=["join_key"], inplace=True)
    return rdf

def crossing_many(*args):
    """
    Computes the cross product of all data frames passed on to it.
    """
    return reduce(crossing, args)