I have the following df called x
buying maint safety
0 vhigh vhigh med
1 vhigh vhigh high
2 vhigh vhigh low
3 vhigh vhigh med
4 vhigh vhigh high
... ... ... ...
1722 low low med
1723 low low high
1724 low low low
1725 low low med
1726 low low high
It has the following values - vhigh, high, med, low
How do I encode this since one hot encoding, ordinal encoding, Label encoding & map encoding only seem to encode pd.series & not pd.df?