columnar_inner_to_dict.py

from json import dumps
from datetime import datetime

# ==============================================================================

def info(msg):
    print(f"{datetime.now().isoformat(' ')[:19]} [INFO] {msg}")

def debug(msg):
    print(f"{datetime.now().isoformat(' ')[:19]} [DEBUG] {msg}")

# ==============================================================================

def apply(data, value, path):
    reverse = path.copy()
    reverse.reverse()
    tmp = {reverse.pop(0): value}
    for x in reverse:
        tmp = {x: tmp}
    for x in path:
        if x in data:
            data = data[x]
            tmp = tmp[x]
        else:
            data[x] = tmp[x]
            break

def main():
    info("START")

    columns = {
        "A": ["Applicant", "Name", "Forename"],
        "B": ["Applicant", "Name", "Surname"],
        "C": ["Applicant", "Gender"],
        "D": ["Original DOB"],
        "E": ["Field1", "Field2", "Field3", "Field4", "Field5"],
        "F": ["Field1", "OtherA"],
    }

    input = [
        {
            "A": "Marcell",
            "B": "Biemann",
            "C": "Male",
            "D": "26/02/1986",
            "F": "abc",
        },
        {
            "A": "Aline",
            "B": "Biemann",
            "C": "Female",
            "D": "13/04/1988",
            "E": "xpto",
        },
    ]

    data = []
    for row in input:
        data_row = {}
        for col in row:
            apply(data_row, row[col], columns[col])
        data.append(data_row)

    debug(f"data =\n{dumps(data, indent=2)}\n")

    info("END")

# ==============================================================================

if __name__ == "__main__":
    main()