Python Coding Challenge - Question with Answer (01261025)

 

Step 1 — Dictionary Creation

d = {'a':1, 'b':2, 'c':3}

Creates a dictionary with:

a → 1
b → 2
c → 3

---

🔹 Step 2 — Getting Keys

d.keys()

Returns a view object of dictionary keys:

dict_keys(['a', 'b', 'c'])

---

🔹 Step 3 — Converting to List

list(d.keys())

Turns that into a list:

['a', 'b', 'c']

---

🔹 Step 4 — Reversing the List

reversed(list(d.keys()))

Creates a reversed iterator:

['c', 'b', 'a']

---

🔹 Step 5 — Looping

for k in reversed(list(d.keys())): 
    print(k, end=' ')

The loop prints each key (k) from the reversed list, separated by a space.

---

Output:

c b a

---

Key Takeaway:

• reversed() works only on sequences like lists or tuples, not directly on dict_keys.

• That’s why we use list(d.keys()).

• Dictionaries in Python preserve insertion order, so reversing the key list prints keys in the opposite order of insertion.

800 Days Python Coding Challenges with Explanation