Python Fundamentals

Cards (24)

• 1
  Front

  What is the correct way to write a comment in Python?

  Back

  Use the # symbol. Everything after # on that line is ignored by the interpreter. Example: # This is a comment

• 2
  Front

  What are the five built-in numeric data types in Python?

  Back

  int (integer), float (floating-point), complex (complex numbers), bool (boolean, a subtype of int), and NoneType (representing None).

• 3
  Front

  How does Python use indentation in its syntax?

  Back

  Python uses indentation (typically 4 spaces) to define code blocks instead of braces. Incorrect indentation causes an IndentationError.

• 4
  Front

  What is the difference between a Python list and a tuple?

  Back

  Lists are mutable (can be changed after creation) and use square brackets []. Tuples are immutable (cannot be changed) and use parentheses ().

• 5
  Front

  How do you create an empty dictionary in Python?

  Back

  Use empty curly braces: my_dict = {} or the dict() constructor: my_dict = dict().

• 6
  Front

  What makes a Python set unique compared to lists and tuples?

  Back

  A set stores only unique elements, is unordered, and is mutable. It does not support indexing or slicing.

• 7
  Front

  How do you access a value in a dictionary by its key?

  Back

  Use bracket notation: my_dict['key'], or the .get() method: my_dict.get('key') which returns None if the key is missing instead of raising a KeyError.

• 8
  Front

  What is list slicing in Python and what is its syntax?

  Back

  List slicing extracts a sub-list. Syntax: list[start:stop:step]. Example: my_list[1:4] returns elements at indices 1, 2, and 3.

• 9
  Front

  What is the syntax for a Python for loop iterating over a list?

  Back

  for item in my_list:
  # do something with item
  The loop runs once for each element in the list.

• 10
  Front

  What is the purpose of the 'elif' keyword in Python control flow?

  Back

  elif (else-if) provides additional conditions to check if the preceding if or elif condition was False. It chains multiple conditional branches.

• 11
  Front

  What is the syntax for defining a function in Python?

  Back

  Use the def keyword followed by the function name, parentheses for parameters, and a colon. Example:
  def my_func(param):
  return param

• 12
  Front

  What is a default parameter value in a Python function?

  Back

  A default value assigned to a parameter in the function definition, used when the caller does not provide that argument. Example: def greet(name='World'):

• 13
  Front

  What do *args and **kwargs represent in a Python function signature?

  Back

  *args collects extra positional arguments into a tuple. **kwargs collects extra keyword arguments into a dictionary.

• 14
  Front

  What is a lambda function in Python?

  Back

  A lambda is an anonymous, single-expression function defined with the lambda keyword. Example: square = lambda x: x ** 2

• 15
  Front

  What is the purpose of the __init__ method in a Python class?

  Back

  __init__ is the constructor method called automatically when a new instance of a class is created. It initializes the instance's attributes.

• 16
  Front

  What is the role of 'self' in a Python class method?

  Back

  self refers to the current instance of the class. It must be the first parameter of every instance method and is used to access instance attributes and other methods.

• 17
  Front

  How do you create a subclass in Python?

  Back

  Pass the parent class as an argument in the class definition. Example:
  class Dog(Animal):
  pass
  Dog inherits all attributes and methods of Animal.

• 18
  Front

  What does the Python 'os' module provide?

  Back

  The os module provides functions for interacting with the operating system, such as file path manipulation (os.path), directory operations (os.listdir), and environment variables (os.environ).

• 19
  Front

  What is the primary use of the Python 'sys' module?

  Back

  The sys module provides access to interpreter-related variables and functions, such as sys.argv (command-line arguments), sys.exit(), and sys.path.

• 20
  Front

  What does the Python 'math' module include?

  Back

  The math module provides mathematical functions and constants such as math.sqrt(), math.pi, math.floor(), math.ceil(), and math.log().

• 21
  Front

  What is a Python list comprehension and what is its syntax?

  Back

  A concise way to create a list. Syntax: [expression for item in iterable if condition]. Example: [x**2 for x in range(10) if x % 2 == 0]

• 22
  Front

  What is the difference between '==' and 'is' in Python?

  Back

  '==' checks if two objects have the same value. 'is' checks if two variables point to the exact same object in memory (identity).

• 23
  Front

  How does a while loop differ from a for loop in Python?

  Back

  A while loop repeats as long as a Boolean condition remains True, whereas a for loop iterates over a defined sequence or iterable a fixed number of times.

• 24
  Front

  What does the 'datetime' module's datetime.now() function return?

  Back

  It returns a datetime object representing the current local date and time, including year, month, day, hour, minute, second, and microsecond.