๐งฎ NumPy Tutorial for Beginners: A Complete Guide to Mastering NumPy
๐ What is NumPy?
NumPy stands for Numerical Python. It’s a powerful open-source Python library used for high-performance numerical and scientific computing. It provides support for arrays, matrices, and a wide variety of mathematical operations.
๐ฆ Why Use NumPy?
- ๐ Faster than standard Python lists for large data operations
- ๐ Supports broadcasting and vectorized operations
- ๐ง Ideal for data science, machine learning, and engineering
๐ Installing NumPy
pip install numpy
๐ฅ To import in your Python script:
import numpy as np
๐ NumPy Arrays Explained
๐น 1D Array Creation
arr = np.array([1, 2, 3, 4])
print(arr)
๐น 2D Array Example
arr2d = np.array([[1, 2], [3, 4]])
print(arr2d)
๐น Array Properties
arr.shape # Dimensions
arr.dtype # Data type
arr.ndim # Number of dimensions
๐ ๏ธ NumPy Array Operations
๐น Element-Wise Arithmetic
a = np.array([10, 20, 30])
b = np.array([1, 2, 3])
print(a + b) # [11 22 33]
print(a * b) # [10 40 90]
๐น Matrix Multiplication
mat1 = np.array([[1, 2], [3, 4]])
mat2 = np.array([[5, 6], [7, 8]])
print(np.dot(mat1, mat2))
๐ฏ NumPy Slicing and Indexing
arr = np.array([10, 20, 30, 40, 50])
print(arr[1:4]) # [20 30 40]
print(arr[-1]) # 50
๐น 2D Array Slicing
arr2d = np.array([[1, 2, 3], [4, 5, 6]])
print(arr2d[0:2, 1]) # [2 5]
๐ Reshaping and Flattening
arr = np.array([[1, 2], [3, 4], [5, 6]])
reshaped = arr.reshape(2, 3)
print(reshaped)
flat = arr.flatten()
print(flat)
๐ข NumPy Functions and Aggregates
๐ Common Methods
np.sum()
np.mean()
np.max()
np.min()
np.std()
arr = np.array([1, 2, 3, 4, 5])
print(np.sum(arr)) # 15
print(np.mean(arr)) # 3.0
๐ Random Numbers with NumPy
print(np.random.rand(3))
print(np.random.randint(1, 10, size=(2, 3)))
๐ง Broadcasting in NumPy
a = np.array([1, 2, 3])
b = 2
print(a + b) # [3 4 5]
๐งน Handling NaN and Missing Values
arr = np.array([1, 2, np.nan, 4])
print(np.isnan(arr)) # [False False True False]
print(np.nanmean(arr)) # 2.333...
๐ก Tips for Better Performance
- ๐ซ Avoid loops; use vectorized operations
- ๐พ Use appropriate dtype to save memory
- ๐งฑ Prefer
np.array
for large datasets
๐ Final Thoughts
NumPy is the backbone of Python-based scientific computing. Its efficient handling of numerical data and powerful API make it a must-learn tool for data analysts, scientists, and engineers.
Start practicing NumPy today to transform your data manipulation skills!
๐ Useful Resources
๐ Summary โ Recap & Next Steps
๐ Key Takeaways:
- NumPy simplifies numerical operations with arrays
- Itโs faster and more memory-efficient than Python lists
- Features like broadcasting, reshaping, and aggregation boost performance
โ๏ธ Real-World Relevance:
- Crucial for data science, AI, ML, and scientific computing
- Forms the base of many popular Python libraries like Pandas, SciPy, and TensorFlow
โ Frequently Asked Questions
โ Is NumPy free to use?
โ Yes, itโs open-source and freely available.
โ Can I use NumPy with Pandas?
โ Absolutely! Pandas is built on top of NumPy.
โ Is NumPy faster than lists?
โ Yes, especially with large-scale operations.
โ Is NumPy only for data science?
โ No. Itโs used across industries โ engineering, physics, finance, and more.
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