# gmlincoln/openweathermap-api-with-python architecture

> Architecture diagram of the GitHub repository gmlincoln/openweathermap-api-with-python, generated by GitDiagram from its file tree, README and a sample of source files (last updated 2026-06-28). It is an AI-made overview: check details against the source.

- Interactive diagram: https://gitdiagram.com/gmlincoln/openweathermap-api-with-python
- Repository: https://github.com/gmlincoln/openweathermap-api-with-python

## Overview

1. **Repository shape**
   This is a very small Python desktop app repo. The visible artifacts are `main.py`, `window.py`, and `README.md`, which points to a single-purpose GUI application rather than a multi-service system.

2. **Primary runtime**
   The app runs as a **Python/Tkinter** desktop program. Tkinter provides the native window, widgets, and event loop; `requests` is used for outbound HTTP calls.

3. **Core responsibility**
   The application’s only business function is to take a **city name** from the user, fetch current weather data from **OpenWeatherMap**, and render the result in the UI.

4. **UI subsystem**
   The GUI consists of a main window, a title label, a text entry for city input, a “Get Weather” button, and a result label. The UI is the primary interaction surface and also the output surface.

5. **Event-driven control flow**
   The app is structured around Tkinter’s event loop. Nothing happens until the user types a city and clicks the button; that button event triggers the weather-fetch function.

6. **External service boundary**
   The only external dependency is the **OpenWeatherMap REST API**. The app sends a GET request with the city name, API key, and metric units, then consumes the returned JSON payload.

7. **Data flow**
   User input flows from the entry widget into a URL string, then into an HTTP request. The response JSON is parsed, key fields are extracted (`name`, `main.temp`, `main.humidity`, `weather[0].description`), and the result label is updated with formatted text.

8. **Error path**
   Non-200 responses are handled with a simple UI message like “City Not Found.” There is no complex retry, validation, or exception orchestration shown in the documentation.

9. **State and persistence**
   The app is stateless beyond the current window contents. It does not persist searches, cache results, store history, or write to disk. The only configuration-like value is the API key.

10. **Likely module boundary**
   With both `main.py` and `window.py` present, the codebase is likely split between **application entry / wiring** and **window/UI logic**, but the README describes the app as one tightly coupled flow rather than separate layers.

11. **Architectural style**
   This is a **single-process, client-only, synchronous GUI app**:
   user input → UI event handler → outbound API request → JSON parsing → UI update. There is no backend, database, message queue, or microservice boundary.

12. **Diagram takeaway**
   For an architecture diagram, the main nodes are: **User**, **Tkinter Desktop UI**, **Weather-fetch logic**, and **OpenWeatherMap API**. The important boundary is between the local GUI process and the external weather service.

Main entry points: [`window.py`](https://github.com/gmlincoln/openweathermap-api-with-python/blob/main/window.py) (HTTP request), [`main.py`](https://github.com/gmlincoln/openweathermap-api-with-python/blob/main/main.py) (App entry)

## Diagram (Mermaid)

```mermaid
flowchart TD

subgraph group_local["Local app"]
  node_entry["App entry<br/>python entry<br/>[main.py]"]
  node_window["Main window<br/>tkinter UI<br/>[window.py]"]
  node_handler["Weather handler<br/>ui logic<br/>[window.py]"]
  node_request["HTTP request<br/>requests client<br/>[window.py]"]
  node_parse["Parse result<br/>json parsing<br/>[window.py]"]
  node_render["Result label<br/>ui output<br/>[window.py]"]
end

subgraph group_external["External service"]
  node_api["OpenWeatherMap<br/>rest api"]
end

node_user(("User<br/>person"))

node_user -->|"enters city"| node_window
node_user -->|"clicks button"| node_handler
node_entry -->|"creates"| node_window
node_window -->|"binds event"| node_handler
node_handler -->|"uses input"| node_request
node_request -->|"GET weather"| node_api
node_api -->|"JSON response"| node_parse
node_parse -->|"formatted text"| node_render
node_request -->|"error path"| node_render

click node_entry "https://github.com/gmlincoln/openweathermap-api-with-python/blob/main/main.py"
click node_window "https://github.com/gmlincoln/openweathermap-api-with-python/blob/main/window.py"
click node_handler "https://github.com/gmlincoln/openweathermap-api-with-python/blob/main/window.py"
click node_request "https://github.com/gmlincoln/openweathermap-api-with-python/blob/main/window.py"
click node_parse "https://github.com/gmlincoln/openweathermap-api-with-python/blob/main/window.py"
click node_render "https://github.com/gmlincoln/openweathermap-api-with-python/blob/main/window.py"

classDef toneNeutral fill:#f8fafc,stroke:#334155,stroke-width:1.5px,color:#0f172a
classDef toneBlue fill:#dbeafe,stroke:#2563eb,stroke-width:1.5px,color:#172554
classDef toneAmber fill:#fef3c7,stroke:#d97706,stroke-width:1.5px,color:#78350f
classDef toneMint fill:#dcfce7,stroke:#16a34a,stroke-width:1.5px,color:#14532d
classDef toneRose fill:#ffe4e6,stroke:#e11d48,stroke-width:1.5px,color:#881337
classDef toneIndigo fill:#e0e7ff,stroke:#4f46e5,stroke-width:1.5px,color:#312e81
classDef toneTeal fill:#ccfbf1,stroke:#0f766e,stroke-width:1.5px,color:#134e4a
class node_entry,node_window,node_handler,node_request,node_parse,node_render toneBlue
class node_api toneAmber
class node_user toneNeutral
```

## Components

### Local app

Python desktop application running on the user machine

- [App entry](https://github.com/gmlincoln/openweathermap-api-with-python/blob/main/main.py): python entry · Starts the Tkinter app and wires the window · `main.py`
- [Main window](https://github.com/gmlincoln/openweathermap-api-with-python/blob/main/window.py): tkinter UI · Desktop window with city input, button, and result label · `window.py`
- [Weather handler](https://github.com/gmlincoln/openweathermap-api-with-python/blob/main/window.py): ui logic · Receives button clicks and coordinates lookup flow · `window.py`
- [HTTP request](https://github.com/gmlincoln/openweathermap-api-with-python/blob/main/window.py): requests client · Builds the OpenWeatherMap GET call from the city name and API key · `window.py`
- [Parse result](https://github.com/gmlincoln/openweathermap-api-with-python/blob/main/window.py): json parsing · Extracts name, temperature, humidity, and description from the response · `window.py`
- [Result label](https://github.com/gmlincoln/openweathermap-api-with-python/blob/main/window.py): ui output · Shows formatted weather details or error text · `window.py`

### External service

Third-party weather API boundary

- **OpenWeatherMap**: rest api · Returns current weather data for the requested city

### Other components

- **User**: person · Types a city name and triggers the lookup

## Connections

- User → Main window: enters city · User types a city into the desktop form
- User → Weather handler: clicks button · Button press starts the weather lookup
- App entry → Main window: creates · Application startup constructs the main window
- Main window → Weather handler: binds event · Tkinter button is wired to the fetch action
- Weather handler → HTTP request: uses input · Handler passes the city name into the request flow
- HTTP request → OpenWeatherMap: GET weather · Sends a synchronous REST request to OpenWeatherMap
- OpenWeatherMap → Parse result: JSON response · Response payload is consumed and decoded locally
- Parse result → Result label: formatted text · Parsed weather fields are rendered in the UI
- HTTP request → Result label: error path · Non-200 responses become a simple city-not-found message