import pandas as pd
from io import StringIO

input_dataframe = pd.read_csv(StringIO("""median_income,distancemeters
1,0
"""))
default_values = {
     "skillmedium": "Phone",
     "campaign": "Phone",
     "distancemeters": 10000,
     "bmi": 31,
     "age": 50,
     "app_source": "PAC",
     "age_median": 45,
     "population": 10000,
     "median_income": 50000
 }
for column, default in default_values.items():
  if column in input_dataframe.columns:
    input_dataframe[column] = input_dataframe[column].fillna(default)
    input_dataframe[column] = input_dataframe[column].replace(0, default)
    
    val=input_dataframe[column].values[0]

    
    if(column == "distancemeters" and val != default):
        milesIntoMeters=val * 1.609 * 1000
        input_dataframe[column] = round(milesIntoMeters, 2)
        print("inside")
        print(input_dataframe[column].values[0])
    print(val)