Modular Code Development
Last updated on 2025-03-13 | Edit this page
Overview
Questions
- What are the benefits of writing modular code in terms of maintenance and scalability?
- How can nested code be targeted and improved through modularization?
Objectives
- Understand the key characteristics that make code modular and why it is advantageous.
- Learn strategies for identifying potential modules within complex code to improve readability and reusability.
What is modularity?
Modularity refers to the practice of building software from smaller, self-contained, and independent elements. Each element is designed to handle a specific set of tasks, contributing to the overall functionality of the system.
We will explain modular coding in the slides. You can view the slides here.
Modularity (20 min)
In a new directory (e.g. mkdir temperature_conversion),
carefully review the following code snippet:
PYTHON
def convert_temperature(temperature, unit):
if unit == "F":
# Convert Fahrenheit to Celsius
celsius = (temperature - 32) * (5 / 9)
if celsius < -273.15:
# Invalid temperature, below absolute zero
return "Invalid temperature"
else:
# Convert Celsius to Kelvin
kelvin = celsius + 273.15
if kelvin < 0:
# Invalid temperature, below absolute zero
return "Invalid temperature"
else:
fahrenheit = (celsius * (9 / 5)) + 32
if fahrenheit < -459.67:
# Invalid temperature, below absolute zero
return "Invalid temperature"
else:
return celsius, kelvin
elif unit == "C":
# Convert Celsius to Fahrenheit
fahrenheit = (temperature * (9 / 5)) + 32
if fahrenheit < -459.67:
# Invalid temperature, below absolute zero
return "Invalid temperature"
else:
# Convert Celsius to Kelvin
kelvin = temperature + 273.15
if kelvin < 0:
# Invalid temperature, below absolute zero
return "Invalid temperature"
else:
return fahrenheit, kelvin
elif unit == "K":
# Convert Kelvin to Celsius
celsius = temperature - 273.15
if celsius < -273.15:
# Invalid temperature, below absolute zero
return "Invalid temperature"
else:
# Convert Celsius to Fahrenheit
fahrenheit = (celsius * (9 / 5)) + 32
if fahrenheit < -459.67:
# Invalid temperature, below absolute zero
return "Invalid temperature"
else:
return celsius, fahrenheit
else:
return "Invalid unit"Refactor the code by extracting functions without altering its functionality.
- What functions did you create?
- What strategies did you use to identify them?
Share your answers in the collaborative document.
PYTHON
def celsius_to_fahrenheit(celsius):
return (celsius * (9 / 5)) + 32
def fahrenheit_to_celsius(fahrenheit):
return (fahrenheit - 32) * (5 / 9)
def celsius_to_kelvin(celsius):
return celsius + 273.15
def kelvin_to_celsius(kelvin):
return kelvin - 273.15
def check_temperature_validity(temperature, unit):
abs_zero = {"C": -273.15, "F": -459.67, "K": 0}
if temperature < abs_zero[unit]:
return False
return True
def check_unit_validity(unit):
if not unit in ["C", "F", "K"]:
return False
return True
def convert_temperature(temperature, unit):
"""
Converts a temperature from one unit to another.
Args:
temperature (float): The temperature to convert.
unit (str): The unit of the temperature. Must be "C", "F", or "K".
Returns:
tuple: A tuple containing the converted temperature in Celsius and Kelvin units.
Raises:
ValueError: If the unit is not "C", "F", or "K".
ValueError: If the temperature is below absolute zero for the given unit.
Examples:
>>> convert_temperature(32, "F")
(0.0, 273.15)
>>> convert_temperature(0, "C")
(32.0, 273.15)
>>> convert_temperature(273.15, "K")
(0.0, -459.67)
"""
if not check_unit_validity(unit):
raise ValueError("Invalid unit")
if not check_temperature_validity(temperature, unit):
raise ValueError("Invalid temperature")
if unit == "F":
celsius = fahrenheit_to_celsius(temperature)
kelvin = celsius_to_kelvin(celsius)
return celsius, kelvin
if unit == "C":
fahrenheit = celsius_to_fahrenheit(temperature)
kelvin = celsius_to_kelvin(temperature)
return fahrenheit, kelvin
if unit == "K":
celsius = kelvin_to_celsius(temperature)
fahrenheit = celsius_to_fahrenheit(celsius)
return celsius, fahrenheit
if __name__ == "__main__":
print(convert_temperature(0, "C"))
print(convert_temperature(0, "F"))
print(convert_temperature(0, "K"))
print(convert_temperature(-500, "K"))
print(convert_temperature(-500, "C"))
print(convert_temperature(-500, "F"))
print(convert_temperature(-500, "B"))PYTHON
class TemperatureConverter:
"""
A class for converting temperatures between Celsius, Fahrenheit, and Kelvin.
"""
def __init__(self):
"""
Initializes the TemperatureConverter object with a dictionary of absolute zero temperatures for each unit.
"""
self.abs_zero = {"C": -273.15, "F": -459.67, "K": 0}
def celsius_to_fahrenheit(self, celsius):
return (celsius * (9 / 5)) + 32
def fahrenheit_to_celsius(self, fahrenheit):
return (fahrenheit - 32) * (5 / 9)
def celsius_to_kelvin(self, celsius):
return celsius + 273.15
def kelvin_to_celsius(self, kelvin):
return kelvin - 273.15
def check_temperature_validity(self, temperature, unit):
if temperature < self.abs_zero[unit]:
return False
return True
def check_unit_validity(self, unit):
if unit not in ["C", "F", "K"]:
return False
return True
def convert_temperature(self, temperature, unit):
if not self.check_unit_validity(unit):
raise ValueError("Invalid unit")
if not self.check_temperature_validity(temperature, unit):
raise ValueError("Invalid temperature")
if unit == "F":
celsius = self.fahrenheit_to_celsius(temperature)
kelvin = self.celsius_to_kelvin(celsius)
return celsius, kelvin
if unit == "C":
fahrenheit = self.celsius_to_fahrenheit(temperature)
kelvin = self.celsius_to_kelvin(temperature)
return fahrenheit, kelvin
if unit == "K":
celsius = self.kelvin_to_celsius(temperature)
fahrenheit = self.celsius_to_fahrenheit(celsius)
return celsius, fahrenheit
if __name__ == "__main__":
converter = TemperatureConverter()
print(converter.convert_temperature(0, "C"))
print(converter.convert_temperature(0, "F"))
print(converter.convert_temperature(0, "K"))
print(converter.convert_temperature(-500, "K"))
print(convert_temperature(-500, "C"))
print(convert_temperature(-500, "F"))
print(convert_temperature(0, "X"))- Software is built from smaller, self-contained elements, each handling specific tasks.
- Modular code enhances robustness, readability, and ease of maintenance.
- Modules can be reused across projects, promoting efficiency.
- Good modules perform limited, defined tasks and have descriptive names.
- Focus on readability and use tests to guide modularization.