Arrays and strings are fundamental data structures in Python. Mastering how to work with them efficiently is essential for day-to-day programming and technical interviews.
Let’s explore the key operations for both arrays and strings in Python, along with simple code examples.
📦 Arrays in Python
In Python, arrays are often represented using lists, which are dynamic and support various operations.
🔁 Traversal
python
arr = [1, 2, 3, 4, 5]
for num in arr:
print(num)
➕ Insertion
python
arr.append(6) # Add to end
arr.insert(2, 10) # Insert 10 at index 2
➖ Deletion
python
arr.remove(3) # Remove first occurrence of 3
del arr[1] # Delete element at index 1
arr.pop() # Remove last element
🔍 Searching
python
if 4 in arr:
print("Found")
🧹 Sorting
python
arr.sort() # In-place sort
sorted_arr = sorted(arr) # Returns a new sorted list
🧵 Strings in Python
Strings are immutable sequences of characters in Python. Most operations return new strings.
🔁 Traversal
python
s = "hello"
for char in s:
print(char)
➕ Insertion (via concatenation)
python
s = "he"
s += "llo" # s becomes "hello"
➖ Deletion (via slicing)
python
s = "hello"
s = s[:2] + s[3:] # Remove character at index 2 → "helo"
🔍 Searching
python
"e" in s # True
s.find("l") # Returns index of first 'l'
🧹 Sorting (convert to list first)
python
sorted_s = ''.join(sorted(s)) # e.g., "hello" → "ehllo"
🧪 Example: Remove Duplicates from an Array
python
nums = [1, 2, 2, 3, 4, 4]
unique = list(set(nums))
print(unique) # Output: [1, 2, 3, 4] (order not guaranteed)
🧪 Example: Reverse a String
python
s = "python"
reversed_s = s[::-1]
print(reversed_s) # Output: "nohtyp"
📝 Final Thoughts
Arrays and strings are everywhere in coding. Understanding their basic operations in Python—like traversal, insertion, and searching—lays the groundwork for solving more complex problems.