Replace items like A2 as AA in the dataframe - python-3.x

Question

I have a list of items, like "A2BCO6" and "ABC2O6". I want to replace them as A2BCO6--> AABCO6 and ABC2O6 --> ABCCO6. The number of items are much more than presented here.
My dataframe is like:
listAB:
Finctional_Group
0 Ba2NbFeO6
1 Ba2ScIrO6
3 MnPb2WO6
I create a duplicate array and tried to replace with following way:
B = ["Ba2", "Pb2"]
C = ["BaBa", "PbPb"]
for i,j in range(len(B)), range(len(C)):
listAB["Finctional_Group"]= listAB["Finctional_Group"].str.strip().str.replace(B[i], C[j])
But it does not produce correct output. The output is like:
listAB:
Finctional_Group
0 PbPbNbFeO6
1 PbPbScIrO6
3 MnPb2WO6
Please suggest the necessary correction in the code.
Many thanks in advance.

Answer 1

I used for simplicity purpose chemparse package that seems to suite your needs.
As always we import the required packages, in this case chemparse and pandas.
import chemparse
import pandas as pd
then we create a pandas.DataFrame object like in your example with your example data.
df = pd.DataFrame(
columns=["Finctional_Group"], data=["Ba2NbFeO6", "Ba2ScIrO6", "MnPb2WO6"]
)
Our parser function will use chemparse.parse_formula which returns a dict of element and their frequency in a molecular formula.
def parse_molecule(molecule: str) -> dict:
# initializing empty string
molecule_in_string = ""
# iterating over all key & values in dict
for key, value in chemparse.parse_formula(molecule).items():
# appending number of elements to string
molecule_in_string += key * int(value)
return molecule_in_string
molecule_in_string contains the molecule formula without numbers now. We just need to map this function to all elements in our dataframe column. For that we can do
df = df.applymap(parse_molecule)
print(df)
which returns:
0 BaBaNbFeOOOOOO
1 BaBaScIrOOOOOO
2 MnPbPbWOOOOOO
dtype: object
Source code for chemparse: https://gitlab.com/gmboyer/chemparse