Feb. 18, 2024, 4:14 p.m.
Python's vast ecosystem of libraries empowers you to tackle diverse programming challenges. Understanding the right tools for your tasks is crucial, and this guide delves into the most valuable libraries across various domains.
Data Science and Machine Learning
import numpy as np
# Create a 3x3 array of random numbers
data = np.random.rand(3, 3)
# Calculate the mean of each row
row_means = np.mean(data, axis=1)
# Print the results
print(data)
print(row_means)
import pandas as pd
# Read a CSV file into a DataFrame
df = pd.read_csv("data.csv")
# Filter rows based on a condition
filtered_df = df[df["column_name"] > 5]
# Group data by category and calculate averages
grouped_df = df.groupby("category").mean()
# Print the results
print(filtered_df)
print(grouped_df)
import matplotlib.pyplot as plt
import seaborn as sns
# Line plot using Matplotlib
data = [1, 3, 5, 7, 9]
plt.plot(data)
plt.show()
# Heatmap using Seaborn
data = np.random.rand(10, 12)
sns.heatmap(data)
plt.show()
from sklearn.linear_model import LinearRegression
# Load training data
X_train, y_train = load_data(training_set)
# Train a linear regression model
model = LinearRegression()
model.fit(X_train, y_train)
# Make predictions on new data
predictions = model.predict(X_test)
# Evaluate model performance
print(model.score(X_test, y_test))
from scipy.optimize import minimize
def objective(x):
return x**2 + 2*x + 3
result = minimize(objective, 0)
print(result.x) # Prints the minimum value's location
import nltk
text = "This is a sample sentence to analyze."
tokens = nltk.word_tokenize(text)
tagged_tokens = nltk.pos_tag(tokens)
print(tokens) # Prints a list of words
print(tagged_tokens) # Prints a list of (word, tag) pairs
# TensorFlow example
import tensorflow as tf
# Define a simple feedforward neural network
model = tf.keras.Sequential([
tf.keras.layers.Dense(128, activation="relu"),
tf.keras.layers.Dense(10, activation="softmax")
])
# Compile and train the model
model.compile(optimizer="adam", loss="sparse_categorical_crossentropy", metrics=["accuracy"])
model.fit(X_train, y_train, epochs=10)
# Evaluate and make predictions
test_loss, test_acc = model.evaluate(X_test, y_test)
predictions = model.predict(X_test)
# Print the results
print(test_acc)
print(predictions)
Web Development
import requests
response = requests.get("https://api.example.com/data")
data = response.json()
print(data)
from flask import Flask, render_template, request
app = Flask(__name__)
@app.route("/")
def index():
return render_template("index.html")
@app.route("/submit", methods=["POST"])
def submit():
data = request.form
# Process data
return "Data submitted successfully!"
if __name__ == "__main__":
app.run(debug=True)
from django.shortcuts import render
from .models import Article
def index(request):
latest_articles = Article.objects.all().order_by("-pub_date")[:5]
context = {"latest_articles": latest_articles}
return render(request, "index.html", context)
from flask import Flask, render_template
app = Flask(__name__)
@app.route("/")
def index():
name = "World"
return render_template("index.html", name=name)
if __name__ == "__main__":
app.run(debug=True)
Automation and Testing
from selenium import webdriver
driver = webdriver.Chrome()
driver.get("https://example.com")
# Find an element by ID
element = driver.find_element_by_id("search_box")
# Enter text and submit
element.send_keys("python")
element.submit()
# Click a button
driver.find_element_by_name("submit").click()
# Close the browser
driver.quit()
import pytest
def test_add():
assert add(2, 3) == 5
def add(a, b):
return a + b
from behave import given, when, then
@given("a user")
def step_impl(context):
pass
@when("they log in")
def step_impl(context):
pass
@then("they should see their profile")
def step_impl(context):
pass
System Administration and DevOps
---
- hosts: all
tasks:
- name: Update the system
apt:
name: "*"
state: upgraded
from docker import Docker
client = Docker()
image = client.images.build(path=".")
container = client.containers.run(image, detach=True)
print(f"Container ID: {container.id}")
Additional Considerations: