Bus

Consider a dictionary (dict) with information about the passengers of an interurban bus. Let’s call it a passengers dictionary (psgD).

The keys in psgD are person identifiers, each composed of a 2-component tuple with a number (int) and one capital letter (str). The values in psgD are 4-component tuple with:

  • the passenger’s name (srt)

  • the row and seat where his/her is supposed to seat (int)

  • the passenger’s destination or stop (srt)

For example:


>>> d = {
... (771, 'L'): ('Vila', 1, 3, 'Amer'),
... (122, 'D'): ('Badosa', 1, 4, 'Olot'),
... (563, 'P'): ('Lopez', 2, 4, 'Olot'),
... (444, 'N'): ('Penosa', 1, 1, 'Amer'),
... (765, 'P'): ('Espigol', 1, 2, 'Amer'),
... }

You are required to implement the following functions and deliver all of them in the same module bus (file bus.py). The tentative weight for each problem is 60%, 10%, 20% and 10% respectively, although the weight of the former function could be increased.

Warning

Do not leave pieces of code that are wither incomplete or contain syntax errors in the file to deliver since that would result in a 0.0 grade for all the functions.

First we need to generate a new dictionary for the bus driver indicating the passengers that are suposed to get off the bus at each stop. To that purpose, you are asked to deliver the following function:

gen_stops_D(psgD)

such that

given psgD a passenger’s dict as described above

returns a new dict where:

  1. The keys are the stops (str) where at least one passenger is supposed to get off. destination.

  2. The value associated to each key is a list with the names of the passengers supposed to get off at that stop.

The input dict should not be modified.

For example:


>>> d = {
... (771, 'L'): ('Vila', 1, 3, 'Amer'),
... (122, 'D'): ('Badosa', 1, 4, 'Olot'),
... (563, 'P'): ('Lopez', 2, 4, 'Olot'),
... (444, 'N'): ('Penosa', 1, 1, 'Amer'),
... (765, 'P'): ('Espigol', 1, 2, 'Amer'),
... }

--in-fi

>>> dcorr = {
... 'Amer' : ['Vila', 'Penosa', 'Espigol'],
... 'Olot': ['Badosa', 'Lopez'],
... }

Doctests are available in the gen_stops_D.test file.

Second, we want the lists in all values of the dict produced by the previous function to be aphabetically ordered:

sort_stops_D(stpD)

such that

given stpD a dict as described for the output of the previous function

updates stpD by alphabetically ordering the names in the lists in its values and nothing else.

For example:



>>> d = {
... 'Amer' : ['Vila', 'Penosa', 'Espigol'],
... 'Olot': ['Lopez', 'Badosa'],
... }

>>> sort_stops_D(d)

>>> dcorr = {
... 'Amer' : ['Espigol', 'Penosa', 'Vila'],
... 'Olot': ['Badosa', 'Lopez'],
... }

Doctests are available in the sort_stops_D.test file.

Third, we need a function to support the change of the destination of a particular passenger given the passenger’s name:

upd_dest_D(psgD, name, newdest)

such that

given psgD a dict as described above

updates psgD by changing the destination of the passenger named name. If there is no passenger with that name in psgD then it is not modified.

returns the passenger identifier (tuple) and his/her new destination (str). If there is no passenger with that name in psgD then the empty tuple is returned as the passenger’s identifier.

For example:


>>> d = {
... (771, 'L'): ('Vila', 1, 3, 'Amer'),
... (122, 'D'): ('Badosa', 1, 4, 'Olot'),
... (563, 'P'): ('Lopez', 2, 4, 'Olot'),
... (444, 'N'): ('Penosa', 1, 1, 'Amer'),
... (765, 'P'): ('Espigol', 1, 2, 'Amer'),
... }

>>> res = upd_dest_D(d, 'Vila', 'Olot')

>>> dref = {
... (122, 'D'): ('Badosa', 1, 4, 'Olot'),
... (563, 'P'): ('Lopez', 2, 4, 'Olot'),
... (444, 'N'): ('Penosa', 1, 1, 'Amer'),
... (765, 'P'): ('Espigol', 1, 2, 'Amer'),
... (771, 'L'): ('Vila', 1, 3, 'Olot'),
... }

>>> if res == ((771, 'L'), 'Olot') and d == dref:
... 	True
... else: 
... 	(res, d)
True

>>> res = upd_dest_D(d, 'Sanchez', 'Olot')

>>> if res == ((), 'Olot') and d == dref:
... 	True
... else: 
... 	(res, d)
True

Doctests are available in the upd_dest_D.test file.

Fourth, we wish to generate and sort a list with the information from a given passengers dict as described above at the beginning above. To that purpose you have to implement the following function:

sort_pass_L(psgD)

such that

given psgD a dict as described above

returns a dict such that

  • It contains exactly the information of the values of psgD, hence a list of tuple.

  • The tuples are ordered according to the following criteria from higher to lower priority:

    1. The name of the distination in alphabetical order.

    2. The number of row in decreasing order.

    3. The name, alphabetically.

For example:


>>> d = {
... (322, 'K'): ('Tulsà', 2, 1, 'Olot'), 
... (771, 'L'): ('Vila', 2, 3, 'Amer'), 
... (122, 'D'): ('Badosa', 1, 4, 'Olot'), 
... (563, 'P'): ('Lopez', 2, 4, 'Olot'), 
... (444, 'N'): ('Penosa', 1, 1, 'Amer'), 
... (765, 'P'): ('Espigol', 1, 2, 'Amer')}

>>> lcorr = [
... ('Vila', 2, 3, 'Amer'),
... ('Espigol', 1, 2, 'Amer'),
... ('Penosa', 1, 1, 'Amer'),
... ('Lopez', 2, 4, 'Olot'),
... ('Tulsà', 2, 1, 'Olot'),
... ('Badosa', 1, 4, 'Olot')]

>>> sort_pass_L(d) == lcorr
True

Doctests are available in the sort_pass_L.test file.