Hari 26: Virtual Environment, pip & Manajemen Paket

Mengapa Virtual Environment?

Setiap project Python mungkin butuh versi library berbeda. Virtual environment membuat isolasi per project sehingga tidak saling konflik.

# Buat virtual environment
python -m venv nama_env

# Aktifkan (Mac/Linux)
source nama_env/bin/activate

# Aktifkan (Windows)
nama_env\Scripts\activate

# Nonaktifkan
deactivate

pip — Package Manager Python

# Install package
pip install requests
pip install pandas==2.0.0       # versi spesifik
pip install "pandas>=1.5,<3.0"  # range versi

# Update package
pip install --upgrade requests

# Uninstall
pip uninstall requests

# Lihat semua package terinstall
pip list
pip freeze                  # format requirements.txt

# Simpan dependensi project
pip freeze > requirements.txt

# Install dari requirements.txt
pip install -r requirements.txt

# Info package
pip show pandas

pyproject.toml & Poetry (Modern)

# Cara modern manajemen project Python
# Install poetry: pip install poetry

# Buat project baru
poetry new myproject

# Tambah dependensi
poetry add requests
poetry add pandas numpy

# Install semua dependensi
poetry install

# Jalankan script
poetry run python main.py

# pyproject.toml
[tool.poetry.dependencies]
python = "^3.10"
requests = "^2.31"
pandas = "^2.0"

Library Populer Python

# Data Science & ML
import numpy as np          # array & matematika
import pandas as pd         # manipulasi data
import matplotlib.pyplot as plt  # visualisasi
import scikit_learn         # machine learning

# Web
import requests             # HTTP client
import flask                # web framework ringan
import fastapi              # web API modern

# Otomasi & Testing
import selenium             # browser automation
import pytest               # unit testing
import black                # code formatter

# Utilitas
import pydantic             # validasi data
import rich                 # output terminal cantik
import arrow                # datetime yang lebih baik

Cek Versi & Environment

import sys
import platform

print(f"Python: {sys.version}")
print(f"OS    : {platform.system()} {platform.release()}")
print(f"Path  : {sys.executable}")

# Cek apakah package tersedia
try:
    import pandas
    print(f"pandas {pandas.__version__} tersedia")
except ImportError:
    print("pandas belum diinstall — pip install pandas")