All Python Methods – List, Tuple, Set and Dictionary with Examples
All Python Methods – List, Tuple, Set and Dictionary
with Examples
You have already learned about Python Lists, Tuples, Sets, and Dictionaries separately. This post is your complete reference guide — all methods of all four data structures in one place, with clear examples and outputs for every single method. Bookmark this page and use it whenever you need a quick reference while coding.
Table of Contents
- Quick Cheat Sheet – All Methods at a Glance
- All List Methods with Examples
- All Tuple Methods with Examples
- All Set Methods with Examples
- All Dictionary Methods with Examples
- Comparison – Which Method Belongs Where
- FAQ
1. Quick Cheat Sheet – All Methods at a Glance
List Methods (11)
- append(x)
- insert(i, x)
- extend(iter)
- remove(x)
- pop(i)
- clear()
- sort()
- reverse()
- index(x)
- count(x)
- copy()
Tuple Methods (2)
- count(x)
- index(x)
Set Methods (15)
- add(x)
- update(iter)
- remove(x)
- discard(x)
- pop()
- clear()
- copy()
- union()
- intersection()
- difference()
- symmetric_difference()
- issubset()
- issuperset()
- intersection_update()
- difference_update()
Dictionary Methods (10)
- keys()
- values()
- items()
- get(k, d)
- update(d)
- pop(k)
- popitem()
- clear()
- copy()
- setdefault(k, v)
2. All List Methods with Examples
Python List – 11 MethodsA list is ordered, mutable, and allows duplicates. It has the most methods out of all four data structures.
| Method | What it does | Syntax |
|---|---|---|
append(x) | Adds item x to the end | list.append(x) |
insert(i, x) | Inserts x at index i | list.insert(1, x) |
extend(iter) | Adds all items from another iterable | list.extend([4,5]) |
remove(x) | Removes first occurrence of x | list.remove(x) |
pop(i) | Removes and returns item at index i | list.pop(0) |
clear() | Removes all items | list.clear() |
sort() | Sorts list in ascending order | list.sort() |
reverse() | Reverses the list in place | list.reverse() |
index(x) | Returns index of first occurrence of x | list.index(x) |
count(x) | Counts how many times x appears | list.count(x) |
copy() | Returns a shallow copy of the list | list.copy() |
append() – Add item to end
fruits = ["Apple", "Banana"] fruits.append("Mango") print(fruits)
['Apple', 'Banana', 'Mango']
insert() – Add item at specific position
fruits = ["Apple", "Mango"] fruits.insert(1, "Banana") # Insert at index 1 print(fruits)
['Apple', 'Banana', 'Mango']
extend() – Merge two lists
list1 = [1, 2, 3] list2 = [4, 5, 6] list1.extend(list2) print(list1)
[1, 2, 3, 4, 5, 6]
extend() adds each item individually. append() adds the entire object as one item. So list.append([4,5]) gives [1,2,3,[4,5]] while list.extend([4,5]) gives [1,2,3,4,5].remove() – Delete by value
nums = [10, 20, 30, 20] nums.remove(20) # Removes FIRST occurrence only print(nums)
[10, 30, 20]
pop() – Delete by index and return value
nums = [10, 20, 30, 40] removed = nums.pop(1) # Remove index 1 print(f"Removed: {removed}") print(nums) nums.pop() # No index = removes last item print(nums)
Removed: 20 [10, 30, 40] [10, 30]
sort() – Sort in ascending or descending order
marks = [85, 42, 90, 67, 55] marks.sort() print("Ascending: ", marks) marks.sort(reverse=True) print("Descending:", marks)
Ascending: [42, 55, 67, 85, 90] Descending: [90, 85, 67, 55, 42]
reverse() – Flip the list order
nums = [1, 2, 3, 4, 5] nums.reverse() print(nums)
[5, 4, 3, 2, 1]
index() and count()
nums = [10, 20, 30, 20, 20] print(nums.index(30)) # Position of 30 print(nums.count(20)) # How many times 20 appears
2 3
clear() and copy()
original = [1, 2, 3] backup = original.copy() # Independent copy original.clear() print("Original:", original) print("Backup: ", backup)
Original: [] Backup: [1, 2, 3]
backup = original if you want an independent copy. That just creates a second reference to the same list — changes to one affect the other. Always use copy().3. All Tuple Methods with Examples
Python Tuple – 2 MethodsA tuple is immutable — once created it cannot be changed. That is why it has only 2 built-in methods. Both are read-only operations.
| Method | What it does | Syntax |
|---|---|---|
count(x) | Returns number of times x appears in the tuple | t.count(x) |
index(x) | Returns index of first occurrence of x | t.index(x) |
count() – Count occurrences
marks = (85, 90, 85, 78, 85, 92) print(marks.count(85)) # How many times 85 appears print(marks.count(99)) # 99 not in tuple
3 0
index() – Find position of a value
fruits = ("Apple", "Banana", "Mango", "Banana") print(fruits.index("Mango")) # Position of Mango print(fruits.index("Banana")) # FIRST occurrence of Banana
2 1
len(), max(), min(), sum(), sorted(), and in operator all work perfectly with tuples.Built-in functions that work with tuples
scores = (88, 92, 75, 60, 95) print("Length: ", len(scores)) print("Maximum:", max(scores)) print("Minimum:", min(scores)) print("Sum: ", sum(scores)) print("Sorted: ", sorted(scores)) # Returns a list print("90 in? ", 90 in scores)
Length: 5 Maximum: 95 Minimum: 60 Sum: 410 Sorted: [60, 75, 88, 92, 95] 90 in? False
4. All Set Methods with Examples
Python Set – 15 MethodsA set is unordered, mutable, and stores only unique values. It has the richest set of mathematical operations.
| Method | What it does |
|---|---|
add(x) | Adds a single item to the set |
update(iter) | Adds multiple items from any iterable |
remove(x) | Removes x — raises KeyError if not found |
discard(x) | Removes x — no error if not found |
pop() | Removes and returns a random item |
clear() | Removes all items |
copy() | Returns a copy of the set |
union(s2) | Returns all items from both sets (A | B) |
intersection(s2) | Returns common items only (A & B) |
difference(s2) | Items in this set but not in s2 (A - B) |
symmetric_difference(s2) | Items not common to both sets (A ^ B) |
issubset(s2) | True if all items of this set are in s2 |
issuperset(s2) | True if this set contains all items of s2 |
intersection_update(s2) | Keeps only common items (modifies in place) |
difference_update(s2) | Removes items that exist in s2 (modifies in place) |
add() and update()
s = {1, 2, 3}
s.add(4)
print(s)
s.update([5, 6, 7])
print(s)
s.update({8, 9}, [10]) # Multiple iterables
print(s){1, 2, 3, 4}
{1, 2, 3, 4, 5, 6, 7}
{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}remove() vs discard()
s = {10, 20, 30}
s.remove(20)
print(s)
s.discard(99) # 99 not in set – no error
print(s)
s.remove(99) # This WILL raise KeyError{10, 30}
{10, 30}
KeyError: 99union(), intersection(), difference(), symmetric_difference()
A = {1, 2, 3, 4}
B = {3, 4, 5, 6}
print("Union: ", A.union(B))
print("Intersection: ", A.intersection(B))
print("Difference A-B: ", A.difference(B))
print("Difference B-A: ", B.difference(A))
print("Symmetric Diff: ", A.symmetric_difference(B))Union: {1, 2, 3, 4, 5, 6}
Intersection: {3, 4}
Difference A-B: {1, 2}
Difference B-A: {5, 6}
Symmetric Diff: {1, 2, 5, 6}issubset() and issuperset()
A = {1, 2}
B = {1, 2, 3, 4}
print(A.issubset(B)) # Is A inside B? True
print(B.issuperset(A)) # Does B contain A? True
print(B.issubset(A)) # Is B inside A? FalseTrue True False
intersection_update() and difference_update()
A = {1, 2, 3, 4}
B = {3, 4, 5, 6}
A.intersection_update(B) # Keeps only common – modifies A
print("After intersection_update:", A)
C = {1, 2, 3, 4}
C.difference_update(B) # Removes items in B from C
print("After difference_update:", C)After intersection_update: {3, 4}
After difference_update: {1, 2}intersection_update() and difference_update() modify the original set in place — no new set is created. Use regular intersection() and difference() when you want to keep the originals unchanged.5. All Dictionary Methods with Examples
Python Dictionary – 10 MethodsA dictionary stores key-value pairs. Its methods are focused on accessing, updating, and managing those pairs.
| Method | What it does |
|---|---|
keys() | Returns a view of all keys |
values() | Returns a view of all values |
items() | Returns a view of all key-value pairs as tuples |
get(key, default) | Returns value for key — returns default if key not found |
update(dict2) | Adds or updates items from another dictionary |
pop(key) | Removes key and returns its value |
popitem() | Removes and returns the last inserted key-value pair |
clear() | Removes all items from the dictionary |
copy() | Returns a shallow copy of the dictionary |
setdefault(key, val) | Returns value if key exists, else inserts key with val |
keys(), values(), items()
student = {"name": "Rohan", "age": 21, "marks": 85}
print(student.keys())
print(student.values())
print(student.items())
# Convert to list
print(list(student.keys()))
print(list(student.values()))dict_keys(['name', 'age', 'marks'])
dict_values(['Rohan', 21, 85])
dict_items([('name', 'Rohan'), ('age', 21), ('marks', 85)])
['name', 'age', 'marks']
['Rohan', 21, 85]get() – Safe value access
student = {"name": "Rohan", "age": 21}
print(student.get("name")) # Rohan
print(student.get("city")) # None – key not found
print(student.get("city", "Unknown")) # "Unknown" – custom defaultRohan None Unknown
update() – Add or change multiple keys
student = {"name": "Rohan", "age": 21}
student.update({"city": "Bengaluru", "age": 22})
print(student){'name': 'Rohan', 'age': 22, 'city': 'Bengaluru'}pop() and popitem()
student = {"name": "Rohan", "age": 21, "city": "Bengaluru"}
val = student.pop("age")
print(f"Removed age: {val}")
print(student)
last = student.popitem()
print(f"Last pair removed: {last}")
print(student)Removed age: 21
{'name': 'Rohan', 'city': 'Bengaluru'}
Last pair removed: ('city', 'Bengaluru')
{'name': 'Rohan'}setdefault() – Add key only if it does not exist
student = {"name": "Rohan", "age": 21}
# Key exists – returns existing value, does NOT change it
print(student.setdefault("age", 99))
# Key does not exist – inserts it with given value
print(student.setdefault("city", "Bengaluru"))
print(student)21
Bengaluru
{'name': 'Rohan', 'age': 21, 'city': 'Bengaluru'}clear() and copy()
original = {"a": 1, "b": 2, "c": 3}
backup = original.copy()
original.clear()
print("Original:", original)
print("Backup: ", backup)Original: {}
Backup: {'a': 1, 'b': 2, 'c': 3}6. Comparison – Which Method Belongs Where
This quick reference table helps you remember which methods are available in which data structure.
| Method | List | Tuple | Set | Dict |
|---|---|---|---|---|
append() | ✅ | ❌ | ❌ | ❌ |
insert() | ✅ | ❌ | ❌ | ❌ |
extend() | ✅ | ❌ | ❌ | ❌ |
add() | ❌ | ❌ | ✅ | ❌ |
update() | ❌ | ❌ | ✅ | ✅ |
remove() | ✅ | ❌ | ✅ | ❌ |
discard() | ❌ | ❌ | ✅ | ❌ |
pop() | ✅ (by index) | ❌ | ✅ (random) | ✅ (by key) |
clear() | ✅ | ❌ | ✅ | ✅ |
copy() | ✅ | ❌ | ✅ | ✅ |
sort() | ✅ | ❌ | ❌ | ❌ |
reverse() | ✅ | ❌ | ❌ | ❌ |
index() | ✅ | ✅ | ❌ | ❌ |
count() | ✅ | ✅ | ❌ | ❌ |
union() / intersection() | ❌ | ❌ | ✅ | ❌ |
keys() / values() / items() | ❌ | ❌ | ❌ | ✅ |
get() / setdefault() | ❌ | ❌ | ❌ | ✅ |
- List has 11 methods — the most out of all four, because it is fully mutable
- Tuple has only 2 methods (count, index) — because it is immutable
- Set has 15 methods — rich with mathematical operations like union and intersection
- Dictionary has 10 methods — focused on key-value access and management
remove()exists in both list and set, but behaves differently — list removes by value, set raises KeyError if not foundpop()exists in list (by index), set (random), and dict (by key) — all different!update()exists in set (adds items) and dict (adds/updates key-value pairs)- Always use
copy()to make an independent copy — never use=for this setdefault()is a powerful dict method — adds key only if it does not already exist
Frequently Asked Questions (FAQ)
Q1. Why does tuple have only 2 methods when list has 11?
Because tuples are immutable — they cannot be changed after creation. All 11 list methods that are missing from tuple (like append, remove, sort) involve modifying the sequence. Since tuples cannot be modified, those methods simply do not exist for them. Only count() and index() are allowed because they just read the data.
Q2. What is the difference between remove() in list and set?
Both remove a specified value. But in a list, if the value appears multiple times, only the first occurrence is removed. In a set, remove() raises a KeyError if the value is not found — use discard() instead for safe removal in sets.
Q3. What is the difference between pop() in list, set, and dictionary?
In a list, pop(i) removes and returns the item at index i (default is the last item). In a set, pop() removes and returns a random item — you cannot control which one. In a dictionary, pop(key) removes and returns the value for the specified key.
Q4. What is the difference between update() in set and dictionary?
In a set, update() adds all items from another iterable (list, set, etc.) to the set. In a dictionary, update() adds new key-value pairs from another dictionary, and also updates existing keys with new values if they already exist.
Q5. How is sort() different from sorted()?
list.sort() modifies the original list directly and returns None. sorted() is a built-in function that works on any iterable, returns a new sorted list, and leaves the original unchanged. sorted() also works on tuples and sets while sort() only works on lists.
Q6. Can I use list methods on a tuple or set?
No. Methods are specific to each data type. You cannot call list.append() on a tuple or set. However, you can convert between types using list(), tuple(), set() functions and then use the appropriate methods on the converted type.
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"Knowing all methods of a data structure is like knowing all the tools in your toolbox — you become unstoppable."
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