List/Tuple: funtions and methods

len()

len() ek built-in function hai jo kisi object mein kitne elements (items) hain, ye batata hai.

Ye List, Tuple, String, Dictionary, Set jaise data structures ke saath use hota hai.

Easy AI/ML/DS Example

Agar dataset mein kitne student records hain, ye dekhna ho to len() use kar sakte ho.

Python Example

marks = [85, 90, 95]

print(len(marks))

Output

3

List Concatenation

List Concatenation ka matlab hai do ya usse zyada Lists ko jodkar (combine karke) ek nayi List banana.

Python mein List Concatenation ke liye + operator use hota hai.

Easy AI/ML/DS Example

Agar ek List mein training data hai aur doosri List mein new data, to dono ko combine karke ek List bana sakte ho.

Python Example

list1 = [10, 20, 30]
list2 = [40, 50]

result = list1 + list2

print(result)

Output

[10, 20, 30, 40, 50]

Membership in list

Membership ka matlab hai check karna ki koi element List mein present hai ya nahi.

Iske liye Python mein in aur not in operators use hote hain.

• in → Element List mein hai ya nahi.

• not in → Element List mein nahi hai ya nahi.

Easy AI/ML/DS Example

Agar check karna ho ki student ka ID dataset mein already present hai ya nahi, to in operator use kar sakte ho.

Python Example

marks = [85, 90, 95]

print(90 in marks)
print(100 in marks)

Output

True
False

not in Example

marks = [85, 90, 95]

print(100 not in marks)

Output

True

.extend()

.extend() ek List method hai jo ek List ke elements ko doosri List ke end mein add karta hai.

Ye poori List ko ek element ki tarah add nahi karta, balki uske har element ko alag-alag add karta hai.

Easy AI/ML/DS Example

Agar tumhare paas old training data aur new training data hai, to .extend() se new data ko old data mein add kar sakte ho.

Python Example

list1 = [10, 20, 30]
list2 = [40, 50]

list1.extend(list2)

print(list1)

Output

[10, 20, 30, 40, 50]

.append()

.append() ek List method hai jo List ke end mein sirf ek element add karta hai.

Ye ek single item add karta hai. Agar List pass karoge, to poori List ek hi element ke roop mein add hogi.

Easy AI/ML/DS Example

Agar dataset mein ek naya student's mark add karna ho, to .append() use kar sakte ho.

Python Example

marks = [85, 90, 95]

marks.append(98)

print(marks)

Output

[85, 90, 95, 98]

List ko append karne ka Example

list1 = [10, 20]
list2 = [30, 40]

list1.append(list2)

print(list1)

Output

[10, 20, [30, 40]]

del

del ek Python keyword hai jo variable ya Data Structure ke elements ko delete (remove) karne ke liye use hota hai.

Ye function nahi, balki keyword hai.

Easy AI/ML/DS Example

Agar dataset se kisi student ka record ya kisi List ka ek element remove karna ho, to del use kar sakte ho.

Python Example (Delete an Element)

marks = [85, 90, 95]

del marks[1]

print(marks)

Output

[85, 95]

Python Example (Delete a Variable)

name = "Umar"

del name

Ab agar:

print(name)

Output

NameError: name 'name' is not defined

.pop()

.pop() ek List method hai jo List se element remove karta hai aur removed element ko return bhi karta hai.

Agar index nahi doge, to ye last element remove karega.

Easy AI/ML/DS Example

Agar dataset se last record remove karna ho aur us record ko baad mein use bhi karna ho, to .pop() use kar sakte ho.

Python Example (Without Index)

marks = [85, 90, 95]

removed = marks.pop()

print(removed)
print(marks)

Output

95
[85, 90]

Python Example (With Index)

marks = [85, 90, 95]

removed = marks.pop(1)

print(removed)
print(marks)

Output

90
[85, 95]

.remove()

.remove() ek List method hai jo di hui value ka pehla occurrence (first matching element) List se remove karta hai.

Ye value ke basis par remove karta hai, index ke basis par nahi.

Easy AI/ML/DS Example

Agar dataset mein ek galat mark 90 store ho gaya hai aur use remove karna hai, to .remove() use kar sakte ho.

Python Example

marks = [85, 90, 95]

marks.remove(90)

print(marks)

Output

[85, 95]

Duplicate Values Example

marks = [85, 90, 95, 90]

marks.remove(90)

print(marks)

Output

[85, 95, 90]

Sirf pehla 90 remove hua hai.

.sort() / .sort(reverse=True)

.sort() ek List ethod mhai jo List ke elements ko ascending (small → large) order mein sort karta hai.

Agar reverse=True use karo, to descending (large → small) order mein sort karta hai.

Easy AI/ML/DS Example

Agar students ke marks ko lowest se highest ya highest se lowest arrange karna ho, to .sort() use karte hain.

Python Example (Ascending Order)

marks = [90, 75, 95, 80]

marks.sort()

print(marks)

Output

[75, 80, 90, 95]

Python Example (Descending Order)

marks = [90, 75, 95, 80]

marks.sort(reverse=True)

print(marks)

Output

[95, 90, 80, 75]

sorted()

sorted() ek built-in function hai jo elements ko ascending order mein arrange karta hai aur ek nayi sorted List return karta hai.

Original data change nahi hota.

Easy AI/ML/DS Example

Agar tum dataset ke marks ko sort karke dekhna chahte ho, lekin original dataset ko change nahi karna chahte, to sorted() use kar sakte ho.

Python Example

marks = [90, 75, 95, 80]

new_marks = sorted(marks)

print(new_marks)
print(marks)

Output

[75, 80, 90, 95]
[90, 75, 95, 80]

Shallow Copy

Shallow Copy b ka matlab hai List ki copy banana, lekin agar List ke andar ek aur List (Nested List) hai, to andar wali List ki alag copy nahi banti.

Yaani dono Lists andar wali same List ko use karti hain.

Isliye agar andar wali List ko change karoge, to original aur copied dono mein change dikhega.

Easy AI/ML/DS Example

Socho ek dataset mein do students ke marks hain:

• Student 1 → [85, 90]

• Student 2 → [75, 80]

Agar tum dataset ki Shallow Copy banaoge aur Student 1 ke marks change karoge, to original dataset ke marks bhi change ho jayenge.

Python Example

list1 = [[1, 2], [3, 4]]

list2 = list1.copy()

list2[0][0] = 100

print(list1)
print(list2)

Output

[[100, 2], [3, 4]]
[[100, 2], [3, 4]]

Kya Hua?

• list2 ek Shallow Copy hai.

• 100 sirf list2 mein change kiya.

• Lekin list1 mein bhi change dikh gaya, kyunki andar wali List dono share kar rahe hain.

split()

split() ek String method hai jo ek String ko chhote parts mein todkar List bana deta hai.

By default, ye underscore ya space ko dekhkar String ko split karta hai.

Easy AI/ML/DS Example

Agar dataset mein ek value "Umar Ahmed Rahmani" hai aur tum first name, middle name, last name alag karna chahte ho, to split() use kar sakte ho.

Python Example

name = "Umar Ahmed Rahmani"

result = name.split()

print(result)

Output

['Umar', 'Ahmed', 'Rahmani']

Tuple Indexing

Tuple Indexing ka matlab hai index number ki help se Tuple ka kisi specific element ko access karna.

Python mein index 0 se start hota hai.

Easy AI/ML/DS Example

Agar Tuple mein student ki information store hai aur sirf Name dekhna hai, to uska index use kar sakte ho.

Python Example

student = (101, "Umar", 22)

print(student[1])

Output

Umar

min()

min() ek built-in function hai jo kisi collection ka sabse chhota (minimum) value return karta hai.

Ye List, Tuple, Set, String jaise data structures ke saath use ho sakta hai.

Easy AI/ML/DS Example

Agar students ke marks ki List hai aur sabse kam marks pata karne hain, to min() use karte hain.

Python Example

marks = [85, 90, 75, 95]

print(min(marks))

Output

75

Yaad rakhne ki Trick

min() = Sabse chhoti value return karta hai.

max()

max() ek built-in function hai jo kisi collection ki sabse badi (maximum) value return karta hai.

Ye List, Tuple, Set, String jaise data structures ke saath use ho sakta hai.

Easy AI/ML/DS Example

Agar students ke marks ki List hai aur sabse zyada marks pata karne hain, to max() use karte hain.

Python Example

marks = [85, 90, 75, 95]

print(max(marks))

Output

95

sum()

sum() ek built-in function hai jo kisi collection ke sabhi numeric values ka total (sum) return karta hai.

Ye List aur Tuple jaise numeric collections ke saath use hota hai.

Easy AI/ML/DS Example

Agar students ke total marks nikalne hain, to sum() use kar sakte ho.

Python Example

marks = [85, 90, 75, 95]

print(sum(marks))

Output

345