Pandas Convert Columns To Percentages Of The Totals

I have a dataframe with 4 columns an ID and three categories that results fell into <80% 80-90 >90 id 1 2 4 4 2 3 6 1 3 7 0 3 I would like to c

Solution 1:

You can do this using basic pandas operators .div and .sum, using the axis argument to make sure the calculations happen the way you want:

cols = ['<80%', '80-90', '>90']
df[cols] = df[cols].div(df[cols].sum(axis=1), axis=0).multiply(100)

• Calculate the sum of each column (df[cols].sum(axis=1). axis=1 makes the summation occur across the rows, rather than down the columns.
• Divide the dataframe by the resulting series (df[cols].div(df[cols].sum(axis=1), axis=0). axis=0 makes the division happen across the columns.
• To finish, multiply the results by 100 so they are percentages between 0 and 100 instead of proportions between 0 and 1 (or you can skip this step and store them as proportions).

Solution 2:

df/df.sum()

If you want to divide the sum of rows, transpose it first.

Solution 3:

Tim Tian's answer pretty much worked for me, but maybe this helps if you have a df with several columns and want to do a % column wise.

df_pct = df/df[df.columns].sum()*100

I was having trouble because I wanted to have the result of a pd.pivot_table expressed as a %, but couldn't get it to work. So I just used that code on the resulting table itself and it worked.

Solution 4:

You could use the apply method:

df = df.apply(lambda x: x/sum(x)*100, axis=1)