Data Types and Other Basic Elements in Python

Welcome to codeswithpankaj.com ! In this tutorial, we will explore Python's data types, how to classify data, and other fundamental elements of a Python program. By the end, you'll have a solid understanding of Python's building blocks.

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Part 1: Comments in Python

What Are Comments?

Comments are used to explain code and make it easier to read. Python ignores comments during execution.

Types of Comments:

1. Single-line Comments Use the # symbol to write single-line comments.

   # This is a single-line comment
   print("Hello, CodesWithPankaj!")  # This prints a message

2. Multi-line Comments Use triple quotes (''' or """) for multi-line comments.

   """
   This is a multi-line comment.
   It can span multiple lines.
   """
   print("Welcome to codeswithpankaj.com!")

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Part 2: Values and Data Types

What Are Data Types?

Data types define the kind of data a variable can hold. Python supports several built-in data types.

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1. Numeric Data Types

Integer (int)

• Whole numbers (positive or negative).

  age = 25
  print(type(age))  # Output: <class 'int'>

Floating-point (float)

• Numbers with decimals.

  price = 19.99
  print(type(price))  # Output: <class 'float'>

Complex Numbers (complex)

• Numbers with real and imaginary parts.

  num = 3 + 4j
  print(type(num))  # Output: <class 'complex'>

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2. Boolean Data Type

• Represents True or False.

  is_valid = True
  print(type(is_valid))  # Output: <class 'bool'>

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3. Compound Data Types

List

• Ordered and mutable collection.

  fruits = ["apple", "banana", "cherry"]
  print(type(fruits))  # Output: <class 'list'>

Tuple

• Ordered and immutable collection.

  coordinates = (10, 20)
  print(type(coordinates))  # Output: <class 'tuple'>

String

• Sequence of characters.

  name = "Pankaj"
  print(type(name))  # Output: <class 'str'>

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4. Dictionary Data Type

• Stores data in key-value pairs.

  user = {"name": "Pankaj", "age": 30}
  print(type(user))  # Output: <class 'dict'>

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5. Set Data Type

• Unordered collection of unique elements.

  numbers = {1, 2, 3, 3, 4}
  print(numbers)  # Output: {1, 2, 3, 4}
  print(type(numbers))  # Output: <class 'set'>

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Part 3: Other Basic Elements of Python Program

1. Identifiers

• Names used to identify variables, functions, or other elements.

• Rules for identifiers:

  • Must start with a letter or underscore.

  • Can contain letters, digits, and underscores.

  • Case-sensitive.

  _name = "CodesWithPankaj"
  user1 = "John"

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2. Keywords

• Reserved words in Python with predefined meanings.

• Examples: if, else, for, while, True, False, etc.

  # Correct usage of a keyword
  if True:
      print("This is a keyword example")

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List of Python Keywords

Python has a specific set of keywords that are reserved and have predefined meanings. They should not be used as variable names. Here's a basic list of Python keywords:

• False

• None

• True

• and

• as

• assert

• async

• await

• break

• class

• continue

• def

• del

• elif

• else

• except

• finally

• for

• from

• global

• if

• import

• in

• is

• lambda

• nonlocal

• not

• or

• pass

• raise

• return

• try

• while

• with

• yield

To obtain the most up-to-date list of Python keywords, you can use the keyword module:

import keyword
print(keyword.kwlist)

3. Variables

• Containers for storing data values.

• Python is dynamically typed, so you don’t need to declare the type explicitly.

Variable Declaration

name = "Pankaj"
age = 30
is_active = True

Multiple Assignments

x, y, z = 10, 20, 30

Reassigning Variables

x = 100  # x now holds a new value

Type Checking

Use the type() function to check the type of a variable.

print(type(name))  # Output: <class 'str'>
print(type(age))   # Output: <class 'int'>

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Examples Summary

Concept	Example Code	Output
Integer Data Type	x = 5; print(type(x))	<class 'int'>
List Data Type	lst = [1, 2, 3]; print(type(lst))	<class 'list'>
Boolean Data Type	flag = True; print(type(flag))	<class 'bool'>
Dictionary Data Type	d = {"key": "value"}; print(type(d))	<class 'dict'>
Variable Declaration	name = "Pankaj"; print(name)	Pankaj
Checking Keywords	import keyword; print(keyword.kwlist)	List of Python keywords

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Conclusion

Python's data types and basic elements form the foundation for programming. Understanding these concepts is essential for building complex programs. Keep practicing, and stay tuned to codeswithpankaj.com for more tutorials!

Happy Coding! 🚀