Python programming is an increasingly important sub-topic of “Basics of Mechatronics” (Section A.2) in the GATE Robotics and Automation (RA) 2027 syllabus. The questions are practical and predictable: trace the output of a snippet, evaluate an operator or expression, follow a loop or conditional, or unwind a recursive function. This guide reviews the core Python constructs on the syllabus and works through six GATE-style output-prediction problems in full.
TABLE OF CONTENTS
Data types & operators
Python’s core types are int, float, str, bool, list, tuple, dict and set. The two operators that trip candidates up are integer division // (floor division) and modulo % (remainder), alongside exponentiation **. Knowing that 17 // 5 = 3 and 17 % 5 = 2 answers a whole class of arithmetic questions.
Conditionals & loops
Control flow uses if / elif / else for branching and for / while for iteration, with break and continue to alter loop flow. The built-in range(a, b) yields a, a+1, …, b−1 — the upper bound is exclusive, which is the single most common source of off-by-one errors.
Functions & recursion
Functions are defined with def and can call themselves (recursion). A recursive function needs a base case and a recursive step: factorial(n) = n × factorial(n−1) with factorial(0) = 1, and the Fibonacci sequence fib(n) = fib(n−1) + fib(n−2). Tracing the call stack gives the answer.
Serious about GATE RA 2027? Get structured video lectures, PYQs, notes and a full test series — taught by Piyush Wairale (IIT Madras).
Strings, lists & dictionaries
Strings and lists support zero-based indexing and slicing s[a:b] (b exclusive), with negative indices counting from the end. List comprehensions build lists concisely, e.g. [x**2 for x in range(5)]. Dictionaries store key–value pairs with O(1) average lookup. These collection operations dominate the coding questions.
Worked examples (GATE-style)
Example 1 — integer division and modulo
What do 17 // 5 and 17 % 5 evaluate to?
Solution. 17 // 5 is the floor of 3.4 = 3; 17 % 5 is the remainder = 2.
Check: 5×3 + 2 = 17. ✓
Example 2 — loop sum
What is the output of s = 0; for i in range(1, 6): s += i; print(s)?
Solution. range(1, 6) gives 1, 2, 3, 4, 5 (6 is excluded). Their sum is 1+2+3+4+5.
Output = 15.
Example 3 — recursion (factorial)
A function is defined as f(n) = 1 if n == 0 else n * f(n-1). What is f(5)?
Solution. This is the factorial: 5 × 4 × 3 × 2 × 1.
f(5) = 120.
Example 4 — string slicing
For s = "robotics", what are s[0:5] and s[-3:]?
Solution. s[0:5] takes indices 0–4 = “robot” (index 5 excluded).
s[-3:] takes the last three characters = “ics”.
Example 5 — list comprehension
What list does [x**2 for x in range(5)] produce?
Solution. x runs over 0, 1, 2, 3, 4; squaring each gives 0, 1, 4, 9, 16.
Output = [0, 1, 4, 9, 16].
Example 6 — recursion (Fibonacci)
With fib(n) = n if n < 2 else fib(n-1) + fib(n-2), what is fib(6)?
Solution. The sequence is fib(0)=0, 1, 1, 2, 3, 5, and fib(6) = fib(5) + fib(4) = 5 + 3.
fib(6) = 8.
Quick reference
QUICK REFERENCE
Floor / mod: 17 // 5 = 3, 17 % 5 = 2
range(a, b): a … b−1 (b excluded)
Slicing: s[a:b] → indices a … b−1
Negative index: s[−1] = last element
Factorial: f(n) = n·f(n−1), f(0) = 1
Comprehension: [x**2 for x in range(5)] = [0,1,4,9,16]
Common mistakes to avoid
- Treating range(a, b) as inclusive — the upper bound b is excluded.
- Confusing / and // — single slash gives a float, double slash floors to an int.
- Off-by-one in slicing — s[a:b] stops at index b−1.
- Missing the recursion base case, which causes infinite recursion.
- Assuming lists and tuples behave the same — tuples are immutable.
GATE ROBOTICS & AUTOMATION 2027
Master Python & Computing for GATE RA
Join the complete GATE RA course by Piyush Wairale (IIT Madras) — full syllabus coverage, PYQs, live doubt-clearing and an exam-focused test series that turns tough topics into guaranteed marks.
Basics of Mechatronics — full solved-problem series
This guide is one part of the Section A.2 (Basics of Mechatronics) solved-problem series. Work through every sub-topic:
See also the umbrella guide, Basics of Mechatronics — Important Questions, and the complete GATE RA 2027 Syllabus.
Frequently asked questions
What is the difference between / and // in Python?
The single slash / performs true division and always returns a float (7 / 2 = 3.5), while the double slash // performs floor division and returns the largest integer not exceeding the quotient (7 // 2 = 3).
Does range(a, b) include b?
No. range(a, b) generates values from a up to b−1; the upper bound is exclusive. So range(1, 6) yields 1, 2, 3, 4, 5 — five values.
Why does a recursive function need a base case?
The base case stops the recursion. Without it, the function keeps calling itself indefinitely until the interpreter raises a “maximum recursion depth exceeded” error. For factorial, the base case is f(0) = 1.
This solved-problems guide is part of the complete GATE RA 2027 Syllabus overview and the Basics of Mechatronics syllabus guide.
Recent Post
GATE PE 2027 Petroleum Engineering syllabus, exam pattern, marks distribution, 2026 cutoff and prep tips, based on the official IIT Madras brochure.
GATE ES 2027 Environmental Science and Engineering syllabus, exam pattern, marking scheme, 2026 cutoff and prep tips from the IIT Madras brochure.
GATE RA 2027 Robotics and Automation syllabus, exam pattern, marks distribution, 2026 cutoff and prep tips, based on the official IIT Madras brochure.
GATE MA 2027 Mathematics syllabus, exam pattern, marks distribution, 2026 cutoff and prep tips, based on the official IIT Madras brochure.
GATE MT 2027 Metallurgical Engineering syllabus, exam pattern, marks distribution, 2026 cutoff and prep tips, based on the official IIT Madras brochure.
GATE NM 2027 Naval Architecture and Marine Engineering syllabus, exam pattern, marking scheme, 2026 cutoff and prep tips from the IIT Madras brochure.
Learn Daily, Wherever You Are
Free lectures, exam updates, PYQ discussions, and job alerts — delivered through our YouTube channel and Telegram communities.
