for each row get frequency of the most frequent value

Question

I have a dataframe that lookS like this:

var1  var2   var3  var4
a      a      a    b
c      c      b    d
e      e      f    g 
g      a      a    z
g      a      a    g
w      w      w    w

what I want to do is to identify the most frequent value for each row and count the number of times it appears, in this case I'd get

var1  var2   var3  var4  frq
a      a      a    b      3
c      c      b    d      2
e      e      f    g      2
g      a      a    z      2
g      a      a    g      2
w      w      w    w      4

I was thinking to use something like pd.get_dummies but there would be too many dummies as each var1, var2 etc may assume quite a few different values

Answer 1

Another way is to apply with axis=1:

df['frq'] = df.apply(lambda x: x.value_counts().iloc[0], axis=1)

Or use stack and groupby:

df['frq'] = df.stack().groupby(level=0).value_counts().max(level=0)