Using a for loop for a dictionary based on user input-CodePudding

airport_code = input("Please enter your code")

airport_values = {
    'BCN':'Barcelona',
    'DUB':'Dublin',
    'LIS':'Lisbon',
    'LHR':'London Heathrow',
    'CDG':'Paris',
    'PRG':'Prague',
    'RKV':'Reykjavik',
    'FCO':'Rome'
}

if airport_code in airport_values:
    print('The value is:', airport_values[airport_code])
else:
    print("Sorry that item is not in the list ")

Hi, I have written this code to find whether or not the key the user enters matches with one of the values stored in the dictionary airport_values.

When I then looked at the mark scheme it then uses a for loop instead to iterate through the whole dictionary and makes use of a counter to check each value.

Here is the pseudocode which is written in the mark scheme.

https://i.stack.imgur.com/huUdQ.png

What I'm wondering is how I would then apply this to python instead of the way I have done it.

Any help would be much appreciated.

CodePudding user response：

Not that this pseudocode doesn't mean that this is the best solution. In python you can directly check in a dict. Also you there is no int indexing in python.

The kind of iteration in a pythonic way could be that way

for key, value in airport_values.items():
    if key == airport_code:
        print('The value is:', value)
        break
else:
    print("Sorry that item is not in the list ")

The exact pseudocode translation is

i = 0
airports = list(airport_values.items())
while airports[i][0] != airport_code:
    i  = 1
print('The value is:', airports[i][1])

CodePudding user response：

for i in airport_values:
  if airport_code in airport_values:
    print('The value is:', airport_values[airport_code])
    break

for more on python for loops: https://www.w3schools.com/python/python_for_loops.asp

CodePudding user response：

airport_values = {
    'BCN':'Barcelona',
    'DUB':'Dublin',
    'LIS':'Lisbon',
    'LHR':'London Heathrow',
    'CDG':'Paris',
    'PRG':'Prague',
    'RKV':'Reykjavik',
    'FCO':'Rome'
}

airports = list(airport_values.items())
code = input("Please enter code")
i = 0
while airports_list[i][0]!=code:
    i=i 1
print("The airport is: " airports[i][1])