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William
William

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🎁Learn Python in 10 Days: Day 1

#python #developer #developers #backend

🎉 From today, I'm going to write a series of 10 articles titled "Learn Python in 10 Days". If you follow along and read diligently, by Day 11, you'll be a proficient Python developer! 🚀

Day 1: Python Basics

1. Literals

Literals are fixed values in your code. Here are some common data types in Python:

Type Description Example
Number (int) Integer value 10, -10
Number (float) Floating-point number 3.14
Number (complex) Complex number 3+4j (ends with j)
Boolean (bool) Represents True/False values True (1), False (0)
String (str) Text "Hello Python!"
List Ordered, mutable collection [1, 2, 3]
Tuple Ordered, immutable collection (1, 2, 3)
Set Unordered, unique items {1, 2, 3}
Dictionary Key-Value pairs {"key": "value"}

2. Comments

Comments explain your code. They aren't executed but can help others understand your code.

  • Single-line comments start with # 
# This prints hello print("hello") # There should be a space after the `#`
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  • Multi-line comments use triple quotes (""") 
""" This is a multi-line comment. It describes the purpose of the code. """
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3. Variables

Variables store data during program execution.

# Define a variable balance = 100 print("Balance:", balance) # Spend $10 balance = balance - 10 print("Balance:", balance)
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4. Data Types

The primary data types you'll encounter:

Type Description Example
int Integer 10
float Floating-point 3.14
str String "Hello!"

Use type() to get the data type.

print(type(10)) # <class 'int'> print(type(3.14)) # <class 'float'> print(type("Hi")) # <class 'str'>
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5. Type Conversion

Convert between data types as needed.

# Convert to string num_str = str(10) # Convert string to integer num_int = int("20") # Convert float to int float_int = int(3.14) # Loses precision
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6. Identifiers

Names for variables, functions, etc. Must follow these rules:

  1. Use letters (a-z, A-Z), digits (0-9), and underscores (_).
  2. Cannot start with a digit.
  3. Case-sensitive.
  4. Can't use Python keywords. 
# Correct i_am_variable = 1 I_Am_Class = "Python" # Incorrect 1_variable = "Nope" class = "Nope" # 'class' is a keyword
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7. Operators

  • Arithmetic operators: +, -, *, /, //, %, **
Operator Description Explanation
+ Addition Adds two objects; a + b outputs the result
- Subtraction Negates a number or subtracts one number from another; a - b outputs the result
* Multiplication Multiplies two numbers or returns a string repeated a certain number of times; a * b outputs the result
/ Division Divides a by b
// Floor Division Returns the integer part of the quotient; 9 // 2 outputs 4
% Modulus Returns the remainder of the division; 9 % 2 outputs 1
** Exponentiation Raises a to the power of b; a ** b 
print("1 + 1 =", 1 + 1) print("5 % 2 =", 5 % 2) # Modulus
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  • Assignment operators: =, +=, -=
Operator Description Example
= Assignment Operator Assigns the value on the right to the variable on the left, e.g., num = 2 * 3 results in num being 6
+= Add AND assignment c += a is equivalent to c = c + a
-= Subtract AND assignment c -= a is equivalent to c = c - a
*= Multiply AND assignment c *= a is equivalent to c = c * a
/= Divide AND assignment c /= a is equivalent to c = c / a
%= Modulus AND assignment c %= a is equivalent to c = c % a
**= Exponent AND assignment c **= a is equivalent to c = c ** a
//= Floor Divide AND assignment c //= a is equivalent to c = c // a 
num = 5 num += 3 # num = num + 3 print(num)
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8. Strings

Definition:

  • Single quotes: 'text'
  • Double quotes: "text"
  • Triple quotes: '''text''' 
name = "John Doe" quote = 'He said, "Python is awesome!"'
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String Concatenation:

greeting = "Hello" + " " + "World" print(greeting)
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String Formatting:

age = 25 message = f"My age is {age}" print(message)
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9. Input

Use input() to get user input.

name = input("Enter your name: ") print(f"Hello, {name}!")
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Stay tuned for more awesome Python tips and tricks in the upcoming days! 🎉

Hope this helps! If you have any more questions, feel free to ask! 😊

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