Pandas equivalent to R expand()-CodePudding

I have the following code in R:

 col1 = 'carrier'
 col2 = 'mode'

 a = tbl %>%
    select(sym(col1), sym(col2))

 tbl2 <- a %>%
    select(sym(col1), sym(col2)) %>%
    expand(!!!syms(c(col1, col2)))

This is the content of tbl:

    carrier mode
3   CRX     ALL
4   GLS     ALL
6   LSR     ALL
7   TFRC    ALL
8   UDS     ALL
11  UPS     GROUND
12  UPS     AIR2
13  UPS     AIR1
14  FEDEX   GROUND
15  FEDEX   AIR2
16  FEDEX   AIR1

And this is the final content of tbl2:

carrier  mode
CRX      AIR1
CRX      AIR2
CRX      ALL
CRX      GROUND
FEDEX    AIR1
FEDEX    AIR2
FEDEX    ALL
FEDEX    GROUND
GLS      AIR1
GLS      AIR2
GLS      ALL
GLS      GROUND
LSR      AIR1
LSR      AIR2
LSR      ALL
LSR      GROUND
TFRC     AIR1
TFRC     AIR2
TFRC     ALL
TFRC     GROUND
UDS      AIR1
UDS      AIR2
UDS      ALL
UDS      GROUND
UPS      AIR1
UPS      AIR2
UPS      ALL
UPS      GROUND

I can see very clearly what R expand() does, but I haven't found an equivalent in Pandas to do so.

CodePudding user response：

You can check with merge , since we do have the method cross , you only need drop_duplicates before pass two columns join

new = df1[['carrier']].drop_duplicates().merge(df1[['mode']].drop_duplicates(),how='cross')

CodePudding user response：

Are you looking for expand_grid from the pandas cookbook?

import itertools

def expand_grid(data_dict):
    rows = itertools.product(*data_dict.values())
    return pd.DataFrame.from_records(rows, columns=data_dict.keys())

expand_grid(tbl.to_dict(orient='list')).drop_duplicates()