Variables in Python act as dynamic references reserved in memory to store objects, operating without explicit data type declarations due to Python’s dynamically typed nature. Built-in primitive and sequence data types including integers (int), floating-point numbers (float), strings (str), booleans (bool), lists (list), tuples (tuple), dictionaries (dict), and sets (set) form the building blocks of data manipulation. A key concept in Python memory management is the distinction between mutable types (whose state can change in place) and immutable types (whose state cannot be altered after creation). This 25-question quiz covers variable initialization, naming conventions, type casting, object identity, mutability, and standard data structures.
1. Which of the following is a valid variable name in Python?
Correct Answer: c) _my_var
Explanation:
Python variable names can contain letters, numbers, and underscores, but they cannot start with a digit, nor can they contain hyphens or spaces.
2. Which built-in function returns the data type of an object in Python?
Correct Answer: b) type()
Explanation:
The built-in type() function returns the exact data type of the specified variable or object.
3. Which of the following data types in Python is immutable?
Correct Answer: d) Tuple
Explanation:
Tuples are immutable sequence types in Python; once initialized, their elements cannot be changed, added, or removed.
4. What is the data type of x after executing x = 5 / 2 in Python 3?
Correct Answer: b) float
Explanation:
In Python 3, the standard division operator (/) always returns a float object (e.g., 2.5), even when both operands are integers.
5. What is the output of type(1_000_000) in Python?
Correct Answer: a) <class 'int'>
Explanation:
Python allows underscores in numeric literals as visual grouping separators. The value 1_000_000 is parsed purely as an integer 1000000.
6. Which of the following is NOT a core built-in numeric type in Python?
Correct Answer: d) double
Explanation:
Python does not have a separate 'double' primitive type. Real numbers with double-precision floating points are simply represented as 'float'.
7. What will be the output of bool(0) and bool(1)?
Correct Answer: b) False, True
Explanation:
The integer 0 evaluates to False in boolean context, whereas any non-zero numeric value evaluates to True.
8. Which keyword is used to declare a variable in Python?
Correct Answer: d) None of the above
Explanation:
Python uses dynamic typing and implicit variable declaration. Variables are created automatically when assigned a value using the '=' operator.
9. What will print(type({1, 2, 3})) output?
Correct Answer: b) <class 'set'>
Explanation:
Curly braces containing comma-separated values without colon key-value pairs define a set object.
10. What will print(type({})) output in Python?
Correct Answer: b) <class 'dict'>
Explanation:
Empty curly braces {} instantiate an empty dictionary by default in Python. An empty set must be instantiated using set().
11. What is the data type of the expression '5' + '5'?
Correct Answer: b) str
Explanation:
Concatenating two string objects produces a string object ('55').
12. Which function converts a float or string representation of a number to an integer by truncating decimals?
Correct Answer: c) int()
Explanation:
The int() built-in function truncates fractional parts of float arguments towards zero and converts integer strings into int.
13. What is the result of type(True)?
Correct Answer: a) <class 'bool'>
Explanation:
True is a boolean literal, which belongs to the built-in class 'bool'.
14. In Python, bool is a subclass of which built-in data type?
Correct Answer: c) int
Explanation:
In Python, bool is explicit subclass of int. True behaves as integer 1 and False behaves as integer 0 in arithmetic operations.
15. Which statement correctly creates a complex number with real part 2 and imaginary part 3?
Correct Answer: b) z = 2 + 3j
Explanation:
Python uses 'j' or 'J' to denote the imaginary unit component of complex numbers.
16. What is the data type of x = (10)?
Correct Answer: b) <class 'int'>
Explanation:
Parentheses surrounding a single item without a trailing comma are interpreted simply as mathematical operator grouping, returning an int.
17. Which syntax correctly defines a single-element tuple?
Correct Answer: c) t = (10,)
Explanation:
A trailing comma is mandatory to distinguish a single-element tuple from standard parenthesized expressions.
18. What is the output of print(isinstance(5.0, int))?
Correct Answer: b) False
Explanation:
5.0 is an instance of float, not int. Thus, isinstance(5.0, int) returns False.
19. What is the result of sys.getsizeof() or general memory allocation characteristics of Python integers?
Correct Answer: c) Arbitrary precision limited only by available memory
Explanation:
Python 3 integers have arbitrary precision, meaning they can grow dynamically as large as available system memory permits.
20. What will print(type(None)) display?
Correct Answer: c) <class 'NoneType'>
Explanation:
None is the sole instance of the built-in NoneType class, indicating absence of a value.
21. Which of the following is a mutable sequence type in Python?
Correct Answer: c) list
Explanation:
Lists are mutable sequence objects, allowing item modifications, additions, and deletions in-place.
22. Which data type represents sequence of immutable Unicode characters?
Correct Answer: a) str
Explanation:
Python 3 'str' objects are immutable sequences of Unicode textual characters.
23. What happens when you execute x, y, z = 1, 2, 3?
Correct Answer: b) x, y, and z are assigned values 1, 2, and 3 respectively
Explanation:
This demonstrates tuple unpacking in multiple assignments, binding x to 1, y to 2, and z to 3.
24. Which statement about variable names in Python is FALSE?
Correct Answer: c) Variable names can start with a digit.
Explanation:
Identifiers/variables in Python cannot start with numbers (0-9).
25. What is the output of print(type(range(5)))?
Correct Answer: c) <class 'range'>
Explanation:
range() returns an immutable sequence object of class 'range', not a list or generator.
26. Which function returns unique memory address identity integer of a variable?
Correct Answer: c) id()
Explanation:
id() returns the unique integer identity (memory address in CPython) of an object.
27. Which of these is an immutable mapping type in standard Python?
Correct Answer: d) Python standard library has no built-in frozendict type
Explanation:
Unlike standard set/frozenset, Python does not feature a built-in immutable 'frozendict' type in core built-ins.
28. What is the output of print('Hello'[1])?
Correct Answer: b) e
Explanation:
Python indexing is 0-based. 'Hello'[0] is 'H', so 'Hello'[1] evaluates to 'e'.
29. Which built-in type represents immutable binary data in Python?
Correct Answer: b) bytes
Explanation:
The 'bytes' class represents immutable sequence streams of 8-bit integers.
30. Which built-in data type represents mutable binary byte arrays?
Correct Answer: b) bytearray
Explanation:
The 'bytearray' class provides a mutable sequence variant of bytes.
31. What is the value of x after x = 3; x += 2 * 4?
Correct Answer: b) 11
Explanation:
Multiplication takes precedence: 2 * 4 = 8. Then += adds 8 to 3, assigning 11 to x.
32. What will print(0.1 + 0.2 == 0.3) output in standard Python?
Correct Answer: b) False
Explanation:
Due to IEEE 754 floating-point binary representation limits, 0.1 + 0.2 yields 0.30000000000000004, making equality False.
33. Which module should be imported for exact fixed-point decimal arithmetic?
Correct Answer: c) decimal
Explanation:
The built-in 'decimal' module provides the Decimal data type for exact monetary/decimal math.
34. What is the output of print(type(frozenset([1, 2])))?
Correct Answer: b) <class 'frozenset'>
Explanation:
frozenset creates an immutable and hashable variant of a set.
35. What happens if you try to modify a character in a string like s = 'cat'; s[0] = 'b'?
Correct Answer: b) TypeError is raised
Explanation:
Strings are immutable; item assignment on str instances triggers a TypeError.
36. Which keyword allows variables defined in inner functions to modify variables in enclosing scopes?
Correct Answer: b) nonlocal
Explanation:
The 'nonlocal' keyword binds identifiers to variables defined in nearest enclosing scope (excluding globals).
37. What is the data type of the variable assigned via x = b'Hello'?
Correct Answer: b) bytes
Explanation:
Prefixing string literals with 'b' creates a 'bytes' object.
38. What will print(type(True + 0)) output?
Correct Answer: b) <class 'int'>
Explanation:
Because bool inherits from int, adding 0 implicitly coerces True (1) to an integer sum 1 of type 'int'.
39. What is the result of type(lambda: None)?
Correct Answer: a) <class 'function'>
Explanation:
Lambda expressions create function objects belonging to class 'function'.
40. Which method checks if all characters in a string variable are numeric digits?
Correct Answer: d) All of the above
Explanation:
isdigit(), isnumeric(), and isdecimal() check different subsets of numeric digit characters.
41. What is the output of print(bool([]), bool([0]))?
Correct Answer: b) False True
Explanation:
An empty list [] evaluates to False, whereas a non-empty list [0] evaluates to True.
42. Which typing module object indicates a variable can be either an int or float?
Correct Answer: c) Both a and b (in Python 3.10+)
Explanation:
Union[int, float] (from typing) and the bitwise OR syntax 'int | float' (Python 3.10+) denote union type hints.
43. Which expression casts float string '3.14' directly into an integer?
Correct Answer: b) int(float('3.14'))
Explanation:
int('3.14') raises ValueError directly. You must parse it to float first, then convert float to int.
44. What will print(type(3 + 4j)) display?
Correct Answer: a) <class 'complex'>
Explanation:
Numbers expressed with a real component and imaginary 'j' suffix are of type 'complex'.
45. What is the value of complex_num.imag for complex_num = 4 + 7j?
Correct Answer: b) 7.0
Explanation:
The .real and .imag attributes of complex numbers return floating-point numbers.
46. Which statement about variable scoping is TRUE?
Correct Answer: b) Variables assigned inside functions are local to that function by default.
Explanation:
Python features function/module level scoping rather than block scoping for control blocks (if, for, while).
47. What is the output of print(a is b) when a = 256 and b = 256 in standard CPython?
Correct Answer: a) True
Explanation:
CPython caches (interns) small integers in the range [-5, 256], so a and b reference identical memory objects.
48. What is the output of print(a is b) when a = 257 and b = 257 in CPython interactive console?
Correct Answer: b) False
Explanation:
Integers greater than 256 are not cached as small integers in CPython interactive shell, creating separate memory instances.
49. Which collection variable cannot contain duplicate elements?
Correct Answer: c) Set
Explanation:
Sets store unique, un-ordered, hashable objects, automatically stripping duplicates.
50. What is the result of type(memoryview(b'abc'))?
Correct Answer: b) <class 'memoryview'>
Explanation:
memoryview objects expose buffer protocol interfaces without copying underlying memory bytes.
51. Which data type is used as keys in a dictionary?
Correct Answer: b) Any hashable object
Explanation:
Dictionary keys must be hashable (meaning their hash value remains constant, like immutable types int, str, tuple).
52. Can a list be used as a key in a Python dictionary?
Correct Answer: b) No, because lists are mutable and unhashable
Explanation:
Lists are mutable and lack __hash__ definitions, raising a TypeError if used as dictionary keys.
53. What will print(type(10 / 2)) output?
Correct Answer: b) <class 'float'>
Explanation:
Division operator '/' always yields a float (5.0), regardless of whether operands divide evenly.
54. What will print(type(10 // 2)) output?
Correct Answer: a) <class 'int'>
Explanation:
Floor division (//) on integer operands yields an integer result (5).
55. What is the type of 10.0 // 2?
Correct Answer: b) <class 'float'>
Explanation:
Floor division with float operands returns a float result with zero decimal component (5.0).
56. Which statement about Python string immutability is TRUE?
Correct Answer: b) String operations like replace() or upper() create new string objects.
Explanation:
Because strings are immutable, methods modifying strings return new string objects instead of mutating originals.
57. What is the output of print(f'{10 + 2}')?
Correct Answer: b) 12
Explanation:
Formatted string literals (f-strings) evaluate expressions inside curly braces at runtime and convert to string.
58. Which method returns a shallow copy of a dictionary variable 'd'?
Correct Answer: b) d.copy()
Explanation:
dict.copy() constructs a shallow copy of the target dictionary.
59. What module provides deep copy functionality for variables?
Correct Answer: a) copy
Explanation:
The standard 'copy' module contains copy.deepcopy() to recursively duplicate nested structures.
60. What is the data type of *args inside a function definition?
Correct Answer: b) tuple
Explanation:
*args packages extra positional arguments into an immutable tuple.
61. What is the data type of **kwargs inside a function definition?
Correct Answer: c) dict
Explanation:
**kwargs packages extra named keyword arguments into a standard dictionary.
62. What is the output of bool('False')?
Correct Answer: b) True
Explanation:
'False' is a non-empty string. Any non-empty string evaluates to True in boolean contexts.
63. What is the result of type(slice(1, 5, 2))?
Correct Answer: b) <class 'slice'>
Explanation:
slice() constructs slice objects representing indexing ranges [start:stop:step].
64. Which statement correctly swaps values of variables a and b?
Correct Answer: b) a, b = b, a
Explanation:
Tuple packing and unpacking swaps references atomically without requiring a temporary variable.
65. What is the type of variable x in x = {i: i**2 for i in range(3)}?
Correct Answer: b) dict
Explanation:
Key: value expression inside curly braces defines a dictionary comprehension.
66. What is the type of variable x in x = {i**2 for i in range(3)}?
Correct Answer: a) set
Explanation:
Single expression within curly braces defines a set comprehension.
67. What is the type of x in x = (i**2 for i in range(3))?
Correct Answer: b) generator
Explanation:
Expressions inside parentheses without list/tuple keywords define generator expressions.
68. What is the default global namespace type accessible via globals()?
Correct Answer: a) <class 'dict'>
Explanation:
globals() returns a reference to the dictionary representing the current global symbol table.
69. Which of the following creates a variable storing a raw string literal?
Correct Answer: a) s = r'Hello\nWorld'
Explanation:
Prefixing string literals with 'r' or 'R' suppresses escape character evaluation.
70. What will print(r'Hello\nWorld') display?
Correct Answer: b) Hello\nWorld
Explanation:
Raw strings treat backslashes '\' as literal characters rather than escape sequences.
71. What is the output of print(type(Ellipsis))?
Correct Answer: a) <class 'ellipsis'>
Explanation:
Ellipsis (or '...') belongs to the built-in singleton class 'ellipsis'.
72. What is the value of x after x = 10; del x?
Correct Answer: c) NameError when accessed
Explanation:
The 'del' statement unbinds variable names; accessing unbound names raises a NameError.
73. What will print(type(int)) output?
Correct Answer: a) <class 'type'>
Explanation:
In Python, classes are themselves instances of the metaclass 'type'.
74. Which function converts integer unicode code points into corresponding single-character strings?
Correct Answer: b) chr()
Explanation:
chr(i) returns the string representing character corresponding to Unicode integer i.
75. Which function returns integer Unicode code point corresponding to a character variable?
Correct Answer: a) ord()
Explanation:
ord(c) returns the integer representation of single Unicode character c.
76. What is the output of ord('A')?
Correct Answer: b) 65
Explanation:
The ASCII / Unicode code point integer for uppercase letter 'A' is 65.
77. Which variable typing assignment conforms to official Python 3.6+ variable type annotation syntax?
Correct Answer: b) age: int = 25
Explanation:
PEP 526 introduced variable type annotations using syntax 'variable: type = value'.
78. Does Python enforce variable type annotations at runtime during code execution?
Correct Answer: b) No, type hints are ignored at runtime and serve static analyzers.
Explanation:
Python remains dynamically typed; type annotations do not raise runtime type errors natively.
79. What is stored in __annotations__ dictionary of a module or class?
Correct Answer: b) Type hints associated with variables and functions
Explanation:
Variable annotations are saved in the __annotations__ attribute dictionary.
80. What is the result of float('inf')?
Correct Answer: b) A float representing positive infinity
Explanation:
float('inf') or float('infinity') parses to floating-point positive infinity.
81. What is the result of type(float('nan'))?
Correct Answer: a) <class 'float'>
Explanation:
NaN (Not a Number) represented by float('nan') is an instance of 'float'.
82. What will print(float('nan') == float('nan')) return?
Correct Answer: b) False
Explanation:
By IEEE 754 standard specification, NaN is explicitly never equal to any value, including itself.
83. Which math module function correctly checks if float variable 'x' is NaN?
Correct Answer: a) math.isnan(x)
Explanation:
Because nan == nan returns False, math.isnan() must be used to test for NaN.
84. What is the value of x after x = 5; x **= 2?
Correct Answer: b) 25
Explanation:
x **= 2 is shorthand for x = x ** 2 (5 squared equals 25).
85. Which builtin method extracts tuple pair of (quotient, remainder) for numeric variables?
Correct Answer: a) divmod()
Explanation:
divmod(a, b) returns a tuple (a // b, a % b).
86. What is the output of divmod(10, 3)?
Correct Answer: a) (3, 1)
Explanation:
10 // 3 equals quotient 3, and 10 % 3 equals remainder 1, returned as (3, 1).
87. What is the data type of the result of hex(255)?
Correct Answer: c) str
Explanation:
The hex() function converts an integer to a lowercase hexadecimal string prefixed with '0x'.
88. What will print(bin(5)) output?
Correct Answer: a) '0b101'
Explanation:
bin() returns binary string representation prefixed with '0b'.
89. Which prefix indicates an octal integer literal in Python?
Correct Answer: a) 0o or 0O
Explanation:
Octal integer literals are prefixed with zero and lowercase/uppercase letter 'o' (e.g., 0o10).
90. Which prefix indicates a hexadecimal integer literal in Python?
Correct Answer: a) 0x or 0X
Explanation:
Hexadecimal numbers start with prefix '0x' or '0X' (e.g., 0xFF).
91. What is the result of int('101', 2)?
Correct Answer: b) 5
Explanation:
Passing base parameter 2 to int() parses string '101' as binary, returning integer 5.
92. What happens when you pass a float variable to math.trunc()?
Correct Answer: b) Returns integer with fractional part eliminated towards zero
Explanation:
math.trunc() truncates decimals returning real integer value.
93. What is the output of round(2.5) and round(3.5) in Python 3?
Correct Answer: b) 2 and 4
Explanation:
Python 3 uses round-half-to-even (Banker's rounding). 2.5 rounds down to 2 and 3.5 rounds up to 4.
94. What is the result of print(type(zip([1], [2])))?
Correct Answer: b) <class 'zip'>
Explanation:
zip() returns an iterator object of type 'zip'.
95. Which statement regarding scope of loop variable 'i' in 'for i in range(5): pass' is TRUE?
Correct Answer: b) 'i' remains accessible in the outer scope with value 4 after loop completion.
Explanation:
For-loops in Python do not create local scope; loop variables persist in surrounding scope.
96. What is the default initial data type returned by input()?
Correct Answer: b) str
Explanation:
The built-in input() function always captures user console input as string.
97. What will print(type(1000000000000000000000000000000)) display in Python 3?
Correct Answer: b) <class 'int'>
Explanation:
Python 3 unified int and long types into a single 'int' type supporting arbitrary precision.
98. What does string method string.encode('utf-8') return?
Correct Answer: b) bytes
Explanation:
Encoding a string converts Unicode str to encoded binary 'bytes'.
99. What does bytes.decode('utf-8') return?
Correct Answer: a) str
Explanation:
Decoding binary bytes converts encoded byte streams back into Unicode text string 'str'.
100. What is the output of print(type(filter(None, [1, 0, 2])))?
Correct Answer: b) <class 'filter'>
Explanation:
filter() returns a filter object iterator of class 'filter'.
101. Which of the following creates a variable reference copy rather than a shallow or deep data copy?
Correct Answer: a) b = a
Explanation:
Simple assignment (b = a) binds b to the exact same object reference in memory.
