NCERT Book Class 11 Computer Science Chapter 9 Lists PDF

Lists is the chapter where Class 11 Computer Science meets the first Python sequence that can be edited after it is built. The ncert book class 11 computer science chapter 9 lists file on this page is the official NCERT chapter for 2026-27. Download it for Table 9.1, all five programs and the complete exercise set.

• Chapter: Chapter 9, Lists
• Book: Computer Science, the Class 11 NCERT textbook for 2026-27, 11 chapters
• File: 18 pages, printed pages 189 to 206, the complete official chapter

You can page through Table 9.1, the five worked programs and both exercise sets in the viewer above before downloading the file.

This is the official NCERT chapter file for the 2026-27 session, hosted by Collegedunia with no pages removed.

How the Lists Chapter Is Laid Out

The chapter opens with a line from Bill Gates about measuring programming progress, then works through eight numbered sections. Each one adds one capability of the list type, and the last section puts all of them together in a single menu driven program.

What the Lists Chapter PDF Contains

The PDF holds the whole chapter exactly as NCERT printed it, with nothing trimmed from either end.

• All eight sections, from the definition of a list to the five manipulation programs
• Table 9.1, the built-in function reference, spread across three printed pages with a runnable shell example beside every method
• Examples 9.1 to 9.5, covering nested lists and all three cloning methods
• Programs 9-1 to 9-5 with their printed output, including the menu driven program with ten choices and the linear search function
• The Summary page, all 7 exercise questions and the 9 programming problems that close the chapter

Lists Class 11 Chapter Overview

Source: Magnet Brains on YouTube

Creating a List, Indexing and the Two Way Index

Section 9.1 defines a list as an ordered sequence that is mutable and made of one or more elements. The elements sit inside square brackets and are separated by commas. Unlike a string, which holds only characters, a list can mix an integer, a float, a string, a tuple or even another list in the same sequence, which is why Example 9.1 shows a list of even numbers, a list of vowels, a list of mixed types and a nested list side by side.

• Forward index: indices start at 0, so list1[0] returns the first element and list1[3] the fourth
• Negative index: list1[-1] returns the first element counted from the right, which is the last element of the list
• Index expressions: anything that evaluates to an integer works, so list1[1+4] is a valid index
• Using len(): if n holds len(list1), then list1[n-1] is the last element and list1[-n] is the first
• IndexError: asking for list1[15] on a six element list raises IndexError: list index out of range, the error the chapter shows first

Why a List Is Mutable When a String Is Not

Section 9.1.2 is short but it carries the idea the rest of the chapter depends on. A list is mutable, meaning its contents can be changed after it has been created. The chapter proves it in two lines: a list of four colours is built, list1[3] is assigned the value 'Black', and printing the list shows the change in place with no new object made.

Strings and tuples behave differently. Assigning to a position inside either one raises a TypeError, so Python has to build a fresh object instead. That single difference decides which methods exist on which type, and it explains why sort() and reverse() belong to lists alone.

List Operations from Concatenation to Slicing

Section 9.2 covers four operations, each with its own set of shell examples you can retype in the lab. All four are read only, which surprises students the first time. Concatenating or slicing a list leaves the original list untouched, so the result has to be assigned to a name if you want to keep it.

The slicing examples are the ones worth reading twice. A second index that runs past the end is simply truncated, so list1[2:20] stops at the last element instead of raising an error. A first index larger than the second returns an empty list. Negative indices work inside a slice, so list1[-6:-2] is legal. And list1[::-1], a step of minus one over the whole list, returns the list in reverse order without changing the original.

Traversing a List with for and while Loops

Section 9.3 gives three ways to visit every element, and exercise question 3 tests the second one directly by printing only the even indexed items.

• The for item loop: writing for item in list1 hands you the element itself on each pass, which is the shortest form and the one to use when you do not need the position
• The range and len loop: for i in range(len(list1)) hands you the index instead, so list1[i] is the element. Use this when the position matters, as it does in Program 9-5
• The while loop: set i to 0, loop while i is less than len(list1), print list1[i] and add one to i. Forgetting the increment is the classic infinite loop in this chapter

List Methods and Built-in Functions in Table 9.1

Section 9.4 is the reference part of the chapter, and Table 9.1 is the page students photograph most often. Every entry pairs a one line description with a shell transcript showing the exact output, so the table doubles as a set of dry run questions.

Two pairs decide most of the marks here. append() against extend() is exercise question 5: appending [50,60] to [10,20,30,40] gives a four element list whose last item is a list, while extending it gives six separate numbers. sort() against sorted() is exercise question 1: sort() changes the list and returns nothing, sorted() returns a new list and changes nothing, which is why calling sorted(list1) on its own line appears to do nothing at all.

Nested Lists, Copying a List and Passing a List to a Function

The last three sections are where mutability starts to have consequences. Section 9.5 introduces the nested list, a list that appears as an element of another list. Reaching an item inside one takes two indices, list1[i][j], where i selects the inner list and j selects the element within it. Exercise question 7 uses this on a student record that holds a name, a roll number, a list of five subject marks and a percentage.

Section 9.6 then draws the line that trips up most students. Writing list2 = list1 does not copy anything. It makes both names refer to the same list object, so list2 is an alias and appending through one name shows up through the other. To get a genuine clone the chapter gives three methods.

• Slicing: newList = oldList[:] takes a full slice, which builds a fresh list
• The list() function: newList = list(oldList) does the same in one call
• The copy library: import copy, then newList = copy.copy(oldList)

All three are shallow copies, so on a nested list the inner lists are still shared and editing one shows up in both. That is the pitfall to watch when a clone seems not to have worked.

Section 9.7 closes the loop with two programs. In Program 9-1 the function edits the elements of the list it receives, and the id() printed inside the function matches the id() printed outside, so the change is visible to the caller. In Program 9-2 the function assigns a brand new list to the parameter name, the id() changes at that moment, and the original list comes back untouched.

What Collegedunia Adds to This Chapter PDF

Collegedunia gives students the file plus a way into it. The chapter PDF itself is the official NCERT file, untouched.

• Official file: the exact NCERT chapter PDF, no pages removed
• Read in the browser: page through all 18 pages before downloading
• Chapter list: jump to any other chapter from one table

Also Check: the other Class 11 Computer Science resources for this chapter.

Class 11 Computer Science NCERT Book PDF: All Chapters

Every chapter of the book is on its own page. The 2026-27 Class 11 Computer Science textbook has 11 chapters, and chapters 5 to 10 form the Python programming block that this chapter sits inside.

Lists Class 11 NCERT Book PDF FAQs