Modules

Topics: Template; Basic Configuration

Understanding modules is essential to organizing your code and taking full advantage of Python’s extensive ecosystem. In healthcare and biomedical research, modules allow you to separate reusable logic — such as calculations, data cleaning, or patient analytics — into organized files.

What Are Modules?

A module is simply a Python file containing functions, classes, and variables.

Any .py file can be imported as a module into another Python script.

Modules help you:

Reuse code across multiple projects
Keep your code organized and maintainable
Share your work with colleagues or research collaborators

Creating Your Own Modules

Let’s create a file named medical_calculator.py — a simple module that performs basic medical computations.

Example: medical_calculator.py

This module provides basic biomedical calculations that could be used in clinical or research contexts.

Let’s define the functions:

def bmi(weight, height):
    """Calculate Body Mass Index."""
    return weight / (height ** 2)

def bsa(weight, height):
    """Calculate Body Surface Area (Mosteller formula)."""
    return ((height * weight) / 3600) ** 0.5

def mean_arterial_pressure(systolic, diastolic):
    """Calculate Mean Arterial Pressure (MAP)."""
    return (2 * diastolic + systolic) / 3

def temperature_c_to_f(celsius):
    """Convert Celsius to Fahrenheit."""
    return (celsius * 9/5) + 32

def temperature_f_to_c(fahrenheit):
    """Convert Fahrenheit to Celsius."""
    return (fahrenheit - 32) * 5/9

Let’s also define module-level variables

You can also define constants that are commonly used in medical calculations.

NORMAL_BMI_RANGE = (18.5, 24.9)
BODY_WATER_PERCENT = 0.6

Code That Runs When the Module Is Imported

print("Medical Calculator module loaded successfully.")

Code That Runs When the Module Is Executed Directly

if __name__ == "__main__":
    print("Running tests for Medical Calculator module...")
    print(f"BMI (70kg, 1.75m): {bmi(70, 1.75):.2f}")
    print(f"BSA (70kg, 175cm): {bsa(70, 175):.2f}")
    print(f"MAP (120/80 mmHg): {mean_arterial_pressure(120, 80):.2f}")

Using Your Module

Now create another file, main.py, where we import and use our module.

import medical_calculator

Use functions from the module:

bmi_value = medical_calculator.bmi(65, 1.68)
map_value = medical_calculator.mean_arterial_pressure(118, 76)

print(f"BMI: {bmi_value:.2f}")
print(f"Mean Arterial Pressure: {map_value:.1f} mmHg")

Alternative import methods

from medical_calculator import bmi, bsa

print(f"BMI: {bmi(58, 1.60):.2f}")
print(f"BSA: {bsa(58, 160):.2f}")

Import With Alias

import medical_calculator as mc

print(f"Temperature: {mc.temperature_c_to_f(37):.1f}°F")

🩺 Why This Matters?

Using modules helps healthcare professionals, researchers, and data analysts reuse and standardize computations across projects.

For example:

Standardize BMI formulas for all datasets
Maintain consistency in how blood pressure is interpreted
Reduce errors when analyzing patient data

Modules make your code modular, reusable, and easier to maintain — crucial for building reliable healthcare tools and analysis pipelines.

Whether you’re creating a clinical calculator, automating data cleaning, or building a patient outcome model, modular programming ensures accuracy, collaboration, and scalability.

Importing Functions from Modules Errors and Exception Handling