Best/most elegant way to divide all of the rows in one pandas DataFrames by an equal-length row in a-CodePudding

I was just wondering whether anyone had a good way to divide a whole Pandas DataFrames (row-by-row) by another row in a different DataFrame.

Example: Say I had one DF that was this: col1: 1 3 col1: 2 4

and another like this: col1: 2 col2: 2

How could I easily arrive at this DF: col1: 0.5 1.5 col2: 1 2

Thanks!

CodePudding user response：

df1 = pd.DataFrame({'a': [1, 3, 5], 'b': [2, 4, 6]})
df2 = pd.DataFrame({'a': [2, 4], 'b': [5, 10]})

df1:
Out[7]: 
   a  b
0  1  2
1  3  4
2  5  6

df2:
   a   b
0  2   5
1  4  10

df3 = df1 divided by first row of df2:

df3 = pd.DataFrame(df1.values / df2.loc[0].values, columns=df1.columns)
df3:
     a    b
0  0.5  0.4
1  1.5  0.8
2  2.5  1.2

CodePudding user response：

Simply use div, or /:

df1.div(df2.iloc[0])
# or
df1/df2.iloc[0]

Output:

     a    b
0  1.0  1.0
1  3.0  2.0

Used input:

df1 = pd.DataFrame({'a': [1, 3], 'b': [2, 4]})
df2 = pd.DataFrame({'a': [1], 'b': [2]})