How to sort pandas dataframe by custom order on string index
As of Pandas 1.1 DataFrame.sort_values has a key
param that takes a callable to control sorting. So you could use an approach like the following:
def sorter(column):
reorder = [
"Maurice Baker",
"Adrian Caldwell",
"Ratko Varda",
"Ryan Bowen",
"Cedric Hunter",
]
# This also works:
# mapper = {name: order for order, name in enumerate(reorder)}
# return column.map(mapper)
cat = pd.Categorical(column, categories=reorder, ordered=True)
return pd.Series(cat)
df_sorted = df.sort_values(by="Player", key=sorter)
There may be some practical differences between using pd.Categorical
and the column.map
alternative I put in the comments. For example, see these caveats. I'm showing both for completeness. I also haven't tested how this compares performance-wise to the current accepted solution that uses df.reindex
. The best approach might be different when you have a MultiIndex
in play too.
To get a custom sort-order on your list of strings, declare it as a categorical and manually specify that order in a sort:
player_order = pd.Categorical([ 'Maurice Baker', 'Adrian Caldwell','Ratko Varda' ,'Ryan Bowen' ,'Cedric Hunter'],
ordered=True)
This is since pandas does not yet allow Categoricals as indices: df.set_index(keys=player_order, inplace=True)
TypeError: unhashable type: 'Categorical'
So you'll want to do a manual custom sort using df.sort_index(level=player_order)
Just reindex
df.reindex(reorderlist)
Out[89]:
Age G Tm Year id
Player
Maurice Baker 25 7 VAN 2004 5335
Adrian Caldwell 31 81 DAL 1997 6169
Ratko Varda 22 60 TOT 2001 13950
Ryan Bowen 34 52 OKC 2009 6141
Cedric Hunter 27 6 CHH 1991 2967
Update info you have multiple players with same name
out = df.iloc[pd.Categorical(df.index,reorderlist).argsort()]