Summary  
This chapter shows how to nest if/else conditionals within a while loop to branch logic for each iteration based on element properties.

General domain of usage  
Processing lists of strings

The **if/else structure** can be combined with a `while` loop to add conditional logic for each iteration. This allows you to perform different actions based on specific conditions while the loop executes.


Let's apply this concept to our `travel_list`. The program will categorize cities as having **short** or **long** names depending on their length (less than 8 characters for short, 8 or more for long).

travel_list = ['Monako', 'Luxemburg', 'Liverpool', 'Barcelona', 'Munchen']

# Initialize index
i = 0

# Categorize cities by name length
while i < len(travel_list):
    if len(travel_list[i]) < 8:
        print(travel_list[i], 'has a short name.')
    else:
        print(travel_list[i], 'has a long name.')
    i += 1

1. The index `i` is initialized to 0 to start from the first city;
2. The `while` loop runs as long as `i` is less than the length of the `travel_list`;
3. **Conditional Logic**:
   - **`if`**: checks if the length of the current city name is less than 8 characters and prints a message accordingly;
   - **`else`**: handles all other cases where the name length is 8 or more characters;
4. The `i` variable is incremented at the end of each iteration to move to the next city.

import unittest
import importlib

def _dynamic_test(test_case, condition, success_message, failure_message):
    if condition:
        test_case._testMethodName = success_message
        test_case.assertTrue(True, success_message)
    else:
        test_case._testMethodName = failure_message
        test_case.fail(failure_message)

class TestUserCode(unittest.TestCase):

    def test_short_name_count_is_declared(self):
        try:
            user_code = importlib.import_module("user_code")
            _ = user_code.short_name_count
            _dynamic_test(self, True, "The `short_name_count` variable is declared.", "")
        except AttributeError:
            _dynamic_test(self, False, "", "Expected `short_name_count` to be declared.")
        except ImportError as e:
            self.fail(f"Failed to import module: {e}")

    def test_short_name_count_is_correct(self):
        try:
            user_code = importlib.import_module("user_code")
            expected_count = sum(1 for country in user_code.countries if len(country) < 7)
            _dynamic_test(
                self,
                user_code.short_name_count == expected_count,
                "The `short_name_count` contains the correct count.",
                f"Expected `short_name_count` to be `{expected_count}`, but got `{user_code.short_name_count}`."
            )
        except AttributeError:
            _dynamic_test(self, False, "", "Expected `short_name_count` to be declared.")
        except ImportError as e:
            self.fail(f"Failed to import module: {e}")

if __name__ == '__main__':
    unittest.main()

test_main.py

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Using Condition Statements in a while Loop

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