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Practical tutorials for the work we actually do. Pick one, read it in order, and apply it.

Any category Programming16 Python 6 JavaScript 4 TypeScript 6 DevOps1 Docker 1
Any topics APIs and Integrations 12 Automation and Scripting 6 Data Structures and Algorithms 8 Databases 32 Deployment and Containers 36 Object-Oriented Programming 7 Packaging and Dependencies 17 Performance Optimization 27 Programming Basics 18 Programming Patterns 12 Security 8 Testing and Debugging 36 Type Systems 35 Web Development 38
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Packaging and Dependencies Clear filters 17 results
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Fix pip Installing Into the Wrong Python Environment

Reproduce an interpreter mismatch, compare executable, pip and module paths, then verify the repair from the Python environment that runs the application.

6 min read
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Test a Python Wheel Outside the Source Repository

Catch a missing package resource by inspecting a wheel and testing its import, version, data file and console command in a clean environment.

6 min read
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Fixing ModuleNotFoundError in Python, One Cause at a Time

ModuleNotFoundError has a handful of causes: the wrong Python, an inactive virtual environment, the wrong folder, or a file that shadows a module. Check them in order instead of reinstalling.

5 min read
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Python if __name__ == "__main__": What It Does and When You Need It

Importing a file runs it. if __name__ == "__main__" keeps a file's script part from running when another file imports it. Use it with a main() function, and know the cases where you don't need it.

4 min read
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Python Is Not Recognized? Fixing PATH on Windows, Mac and Linux

Python is probably installed. Your terminal just can't find it. Check the three possible causes in order, fix the right one on Windows, Mac or Linux, and confirm which Python you're really running.

6 min read
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pip freeze vs Writing requirements.txt by Hand: Which One to Use

pip freeze gives exact versions but hides what you chose. A hand-written file shows what you chose but isn't exact. For anything you deploy, keep both: one file for intent, one frozen for exact versions.

5 min read
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Fix "Cannot use import statement outside a module"

The file was loaded as a classic script or CommonJS, where import isn't allowed. The fix in the browser is type="module". In Node it's "type": "module" or .mjs, and recent npm init writes "type": "commonjs" for you.

5 min read
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Install Node.js and Check It Actually Works

Install the LTS version of Node.js, check the installer's signature, and prove it works in a new terminal with node -v, npm -v and one real install. Plus the fixes for "not recognized" and the wrong version showing.

5 min read
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npm install vs npm ci: Same Install on Every Machine

Use npm ci to install exactly what the lock file says and npm install to change it. What each command does, when to use which, and how to fix "npm ci can only install packages when your package.json and package-lock.json are in sync".

5 min read
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Build and Publish a Small npm Package

Set up name, version, exports and files in package.json, check exactly what ships with npm pack --dry-run, then publish with npm publish. Mistakes in a published version can't be undone.

4 min read
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Find Which TypeScript Compiler Your Project Runs

Trace a compiler version mismatch, confirm the resolved package path, and make a project-local check catch a deliberate type error.

5 min read
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Export Types From a Module Without Runtime Code

Compare import type, the inline type keyword and a plain import, and see which ones leave code in the compiled file. After this, a types-only import cannot load a module with side effects.

4 min read