Lower_case the dictionary keys and values-CodePudding

I have a function that should return true for case-in-sensitive keys and values for a US_STATES

from localflavor.us.us_states import US_STATES

def check_state(value):
    return value in dict(US_STATES).values())
print(US_STATES)

And the result is :

(('AK', 'Alaska'), ('AL', 'Alabama'), ('AR', 'Arkansas'), ('AZ', 'Arizona'), ('CA', 'California'), ('CO', 'Colorado'), ('CT', 'Connecticut'), ('DC', 'District of Columbia'), ('DE', 'Delaware'), ('FL', 'Florida'), ('GA', 'Georgia'), ('HI', 'Hawaii'), ('IA', 'Iowa'), ('ID', 'Idaho'), ('IL', 'Illinois'), ('IN', 'Indiana'), ('KS', 'Kansas'), ('KY', 'Kentucky'), ('LA', 'Louisiana'), ('MA', 'Massachusetts'), ('MD', 'Maryland'), ('ME', 'Maine'), ('MI', 'Michigan'), ('MN', 'Minnesota'), ('MO', 'Missouri'), ('MS', 'Mississippi'), ('MT', 'Montana'), ('NC', 'North Carolina'), ('ND', 'North Dakota'), ('NE', 'Nebraska'), ('NH', 'New Hampshire'), ('NJ', 'New Jersey'), ('NM', 'New Mexico'), ('NV', 'Nevada'), ('NY', 'New York'), ('OH', 'Ohio'), ('OK', 'Oklahoma'), ('OR', 'Oregon'), ('PA', 'Pennsylvania'), ('RI', 'Rhode Island'), ('SC', 'South Carolina'), ('SD', 'South Dakota'), ('TN', 'Tennessee'), ('TX', 'Texas'), ('UT', 'Utah'), ('VA', 'Virginia'), ('VT', 'Vermont'), ('WA', 'Washington'), ('WI', 'Wisconsin'), ('WV', 'West Virginia'), ('WY', 'Wyoming'))

This function returns true only for values but I also need to return true for keys which are state codes and the function should return true for Case-insesitive key-value pairs.

CodePudding user response：

I'm not using Django (which you obviously are) so let's work from basics:

STATES = (('AK', 'Alaska'), ('AL', 'Alabama'), ('AR', 'Arkansas'), ('AZ', 'Arizona'), ('CA', 'California'), ('CO', 'Colorado'), ('CT', 'Connecticut'), ('DC', 'District of Columbia'), ('DE', 'Delaware'), ('FL', 'Florida'), ('GA', 'Georgia'), ('HI', 'Hawaii'), ('IA', 'Iowa'), ('ID', 'Idaho'), ('IL', 'Illinois'), ('IN', 'Indiana'), ('KS', 'Kansas'), ('KY', 'Kentucky'), ('LA', 'Louisiana'), ('MA', 'Massachusetts'), ('MD', 'Maryland'), ('ME', 'Maine'), ('MI', 'Michigan'), ('MN', 'Minnesota'), ('MO', 'Missouri'), ('MS', 'Mississippi'),
          ('MT', 'Montana'), ('NC', 'North Carolina'), ('ND', 'North Dakota'), ('NE', 'Nebraska'), ('NH', 'New Hampshire'), ('NJ', 'New Jersey'), ('NM', 'New Mexico'), ('NV', 'Nevada'), ('NY', 'New York'), ('OH', 'Ohio'), ('OK', 'Oklahoma'), ('OR', 'Oregon'), ('PA', 'Pennsylvania'), ('RI', 'Rhode Island'), ('SC', 'South Carolina'), ('SD', 'South Dakota'), ('TN', 'Tennessee'), ('TX', 'Texas'), ('UT', 'Utah'), ('VA', 'Virginia'), ('VT', 'Vermont'), ('WA', 'Washington'), ('WI', 'Wisconsin'), ('WV', 'West Virginia'), ('WY', 'Wyoming'))

statesByCode = {k.lower(): v.lower() for k, v in STATES} # keyed on lowercase state code
statesByState = {v.lower(): k.lower() for k, v in STATES} # keyed on lowercase state name

Just create two dictionaries where the 'normal form' of the keys is lowercase. One dictionary is keyed on state code the other on state name.

Then you can do this:

def check_state(value):
  return value.lower() in statesByCode

Thus you can easily (and very quickly) check if a given state code is valid.

e.g.,

check_state('Co')

...would return True

Similar for states (full names):

def check_state_name(value):
  return value.lower() in statesByState

e.g.,

check_state_name('ALabamA')

...would return True