Apply a padding function to .csv columns (Pandas)

pandas_pad_using_apply.py

# example of using a parameterized function as a converter when reading .csv in pandas

import pandas as pd

# a function that will be used to pad datafram column values to a specified length
# (some incoming values are multiple spaces; those should convert to Noe)
padFunction = lambda field, padTo: str(field).strip().zfill(padTo) if len(str(field).strip()) else None

# read file w/o using converters and display list of unique alloc_id values
pa = pd.read_csv(
  'https://raw.githubusercontent.com/fedspendingtransparency/data-act-broker-backend/master/dataactvalidator/config/program_activity.csv'
)
print(pd.unique(pa.alloc_id.ravel()))

# apply padding function to pad columns after file is read in
pa.account = pa.account.apply(padFunction, padTo=4)
pa.pa_code = pa.pa_code.apply(padFunction, padTo=4)
pa.alloc_id = pa.alloc_id.apply(padFunction, padTo=3)
pa.agency_id = pa.agency_id.apply(padFunction, padTo=3)
print(pd.unique(pa.alloc_id.ravel()))

pandas_pad_using_converters.py

# example of using a parameterized function as a converter when reading .csv in pandas

import pandas as pd

# a function that will be used to pad datafram column values to a specified length
# (some incoming values are multiple spaces; those should convert to Noe)
padFunction = lambda field, padTo: str(field).strip().zfill(padTo) if len(str(field).strip()) else None

converters = {
  'agency_id': lambda x: padFunction(x, 3),
  'alloc_id': lambda x: padFunction(x, 3),
  'pa_code': lambda x: padFunction(x, 4),
  'account': lambda x: padFunction(x, 4),
}

# read file w/o using converters and display list of unique alloc_id values
pa = pd.read_csv(
  'https://raw.githubusercontent.com/fedspendingtransparency/data-act-broker-backend/master/dataactvalidator/config/program_activity.csv'
)
print(pd.unique(pa.alloc_id.ravel()))

# now read file using converters and display list of unique alloc_id values (should be zero-padded to length of 3)
pa = pd.read_csv(
  'https://raw.githubusercontent.com/fedspendingtransparency/data-act-broker-backend/master/dataactvalidator/config/program_activity.csv',
  converters=converters
)
print(pd.unique(pa.alloc_id.ravel()))