have two variable list and hoping to work on some calculation of the two list-CodePudding

I am hoping to create few new columns for 'data'. The first created col is a/d, second b/e, and third c/f.

col1 is a list of names for the original columns The output of df should look like this

a  b  c  d  e  f  res_a  res_c  res_e
1  2  3  4  2  3  0.5    0.75   2/3

res_a is a divide b a = 1, b = 2, therefore res_a = 1/2 = 0.5 c/d c = 3, d= 4 res_c = 3/4 = 0.75

my code looks like this now, but I can't get a/b, c/d, and e/f

col1 = ['a', 'b', 'c']
col2 = ['d', 'e', 'f']
for col in cols2:
    data[f'res_{col}'] = np.round(data[col1]/ data[col2],decimals=2)

CodePudding user response：

You could also use the pandas.IndexSlice to pick up alternate columns with a list slicing type of syntax

cix = pd.IndexSlice
df[['res_a', 'res_c', 'res_e']] = np.divide(df.loc[:, cix['a'::2]], df.loc[:, cix['b'::2]])
print(df)

#    a  b  c  d  e  f  res_a  res_c     res_e
# 0  1  2  3  4  2  3    0.5   0.75  0.666667

You can read more about the pandas slicers

CodePudding user response：

Use zip() to loop over two lists in parallel.

cols1 = ['a', 'c', 'e']
cols2 = ['b', 'd', 'f']
for c1, c2 in zip(cols1, cols2):
    data[f'res_{c1}'] = np.round(data[c1] / data[c2], decimals=2)