Python lists come with a variety of built-in methods that allow you to perform common operations such as adding, removing, or searching for elements. Understanding these methods is crucial for efficient list manipulation.
Common List Methods:
append(item) - Adds an item to the end of the list.
insert(index, item) - Inserts an item at a specified position.
remove(item) - Removes the first occurrence of an item from the list.
pop(index) - Removes and returns the item at the specified position. If no index is specified, it removes and returns the last item.
clear() - Removes all items from the list, resulting in an empty list.
index(item) - Returns the index of the first occurrence of an item. Raises a ValueError if the item is not found.
count(item) - Returns the number of times an item appears in the list.
sort() - Sorts the list in ascending order by default. You can pass reverse=True to sort in descending order.
reverse() - Reverses the order of the list in place.
copy() - Returns a shallow copy of the list.
Examples:
Python
fruits = ["apple", "banana", "cherry"]
# Append an item
fruits.append("date")
print(fruits) # Output: ["apple", "banana", "cherry", "date"]
# Insert an item at index 1
fruits.insert(1, "blueberry")
print(fruits) # Output: ["apple", "blueberry", "banana", "cherry", "date"]
# Remove an item
fruits.remove("banana")
print(fruits) # Output: ["apple", "blueberry", "cherry", "date"]
# Sort the list in ascending order
fruits.sort()
print(fruits) # Output: ["apple", "blueberry", "cherry", "date"]
# Reverse the order of the list
fruits.reverse()
print(fruits) # Output: ["date", "cherry", "blueberry", "apple"]
# Get the index of an item
index = fruits.index("cherry")
print(index) # Output: 1
# Count occurrences of an item
count = fruits.count("apple")
print(count) # Output: 1
# Copy the list
copied_fruits = fruits.copy()
print(copied_fruits) # Output: ["date", "cherry", "blueberry", "apple"]
# Clear the list
fruits.clear()
print(fruits) # Output: []
These methods are fundamental to working with lists and provide powerful tools for list manipulation, allowing you to easily manage and transform list data.
List Methods in Python
Python lists ke sath kaam karne ke liye kai built-in methods aati hain jo aapko common operations perform karne mein help karti hain, jaise ki elements add karna, remove karna, ya search karna. In methods ko samajhna list manipulation ke liye zaroori hai.
Common List Methods:
append(item) - Ek item ko list ke end mein add karta hai.
insert(index, item) - Kisi specific position par item insert karta hai.
remove(item) - List mein se kisi item ki first occurrence ko remove karta hai.
pop(index) - List mein se specified position par jo item hai usse remove karke return karta hai. Agar index specify nahi kiya ho to last item ko remove karta hai.
clear() - List ke saare items ko remove kar deta hai, result mein ek empty list milti hai.
index(item) - List mein kisi item ki first occurrence ka index return karta hai. Agar item nahi milta to ValueError raise karta hai.
count(item) - List mein kisi item ki kitni baar occurrence hui hai, ye batata hai.
sort() - List ko ascending order mein sort karta hai. Aap reverse=True pass karke descending order mein bhi sort kar sakte ho.
reverse() - List ka order reverse karta hai, inplace.
copy() - List ka shallow copy return karta hai.
Examples:
Python
fruits = ["apple", "banana", "cherry"]
# Append ek item
fruits.append("date")
print(fruits) # Output: ["apple", "banana", "cherry", "date"]
# Index 1 par ek item insert karo
fruits.insert(1, "blueberry")
print(fruits) # Output: ["apple", "blueberry", "banana", "cherry", "date"]
# Ek item remove karo
fruits.remove("banana")
print(fruits) # Output: ["apple", "blueberry", "cherry", "date"]
# List ko ascending order mein sort karo
fruits.sort()
print(fruits) # Output: ["apple", "blueberry", "cherry", "date"]
# List ka order reverse karo
fruits.reverse()
print(fruits) # Output: ["date", "cherry", "blueberry", "apple"]
# Kisi item ka index nikalna
index = fruits.index("cherry")
print(index) # Output: 1
# Kisi item ki occurrence count karo
count = fruits.count("apple")
print(count) # Output: 1
# List ka copy banao
copied_fruits = fruits.copy()
print(copied_fruits) # Output: ["date", "cherry", "blueberry", "apple"]
# List ko clear karo
fruits.clear()
print(fruits) # Output: []
Ye methods lists ke sath kaam karne mein fundamental hain aur aapko list manipulation ke liye powerful tools dete hain, jo aapko asani se list data ko manage aur transform karne mein madad karte hain.
Import Links
Here are some useful import links for further reading: