Akuli · Akuli · Sep 10, 2022 · Sep 6, 2022 · Sep 7, 2022 · Sep 7, 2022
diff --git a/basics/trey-hunner-zip-and-enumerate.md b/basics/trey-hunner-zip-and-enumerate.md
@@ -1,4 +1,4 @@
-# Trey Hunner: zip and enumerate
+# zip and enumerate
 
 Now we know how [for loops](loops.md#for-loops) work in Python. But
 for loops aren't limited to printing each item in a list, they can
@@ -75,63 +75,138 @@ b 2
 c 3
 >>>
 ```
+[comment]: # (Zip and Enumerarate by Tushar starts here)
 
-Now you're ready to read [this awesome looping
-tutorial](http://treyhunner.com/2016/04/how-to-loop-with-indexes-in-python/).
-Read it now, then come back here and do the exercises.
-
-## Exercises
-
-1. Create a program that works like this. Here I entered everything
-    after the `>` prompt that the program displayed.
-
-    ```
-    Enter something, and press Enter without typing anything when you're done.
-    >hello there
-    >this is a test
-    >it seems to work
-    >
-    Line 1 is: hello there
-    Line 2 is: this is a test
-    Line 3 is: it seems to work
-    ```
-
-2. Create a program that prints all letters from A to Z and a to z
-    next to each other:
-
-    ```
-    A a
-    B b
-    C c
-    ...
-    X x
-    Y y
-    Z z
-    ```
-
-    Start your program like this:
-
-    ```python
-    uppercase = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
-    lowercase = 'abcdefghijklmnopqrstuvwxyz'
-    ```
-
-    **Hint:** how do strings behave with `zip`? Try it out on the
-    `>>>` prompt and see.
-
-3. Can you make it print the indexes also?
-
-    ```
-    1 A a
-    2 B b
-    3 C c
-    ...
-    24 X x
-    25 Y y
-    26 Z z
-    ```
-
-The answers are [here](answers.md).
+## zip
+
+What comes to your mind when you hear the word `zip`? A mechanism extensively used to tie two parts of something i.e. Shirt, Jacket etc. The `zip()` functions does pretty much same, it helps us tie two or more different items together.
+
+### Syntax
+
+`zip(iterator1, iterator2, iterator3 ...) `
+
+### Parameter Values
+
+`zip()` can take 2 or more iterator values like so `zip(iterator1, iterator2, iterator3....)`. These
+iterators will be joined together once the function is executed.
+
+### Example 1
+
+Let's look at an example, suppose we wish to join 2 tuples together.
+
+```python
+>>> users = ("Tushar", "Aman", "Anurag", "Sohit")
+uids = ("usr122", "usr123", "usr124", "usr125")
+user_details = zip(uids, users)
+print(user_details)
+>>>
+<zip object at 0x149648b0d5c0>
+>>>
+```
+
+If we want to get some real output we can convert this zip object into List, tuple or a set.
+
+### Example 2
+
+```python
+>>> users = ("Tushar", "Aman", "Anurag", "Sohit")
+uids = ("usr122", "usr123", "usr124", "usr125")
+user_details = zip(uids, users)
+print(list(user_details)) # converting to list
+>>>
+[('usr122', 'Tushar'), ('usr123', 'Aman'), ('usr124', 'Anurag'), ('usr125', 'Sohit')]
+>>>
+```
+
+What if these iterators were of different lengths? well, then the ones with the extra fields will be ignored like so.
+
+### Example 3
+
+```python
+>>> users = ("Tushar", "Aman", "Anurag", "Sohit") 
+uids = ("usr122", "usr123", "usr124") 
+emails = ("tushar@example.com", "aman@example.com", "anurag@example.com", "sohit@example.com")
+user_details = zip(uids, users, emails)
+print(list(user_details))
+>>>
+[('usr122', 'Tushar', 'tushar@example.com'), ('usr123', 'Aman', 'aman@example.com'), ('usr124', 'Anurag', 'anurag@example.com')]
+>>>
+```
+
+Length of `uids` is 3 thus it is the shortest tuple, now `zip()` function will crop other tuples to consider them equally and will finally join all of them together.
+
+### Example 4: Using zip with for loop
+
+```python
+>>> roll_nums = (20, 25, 28) 
+students = ("Joe", "Max", "Michel")
+>>> for roll_num, student in zip(roll_nums, students):
+...     print(f"Roll number of {student} is {roll_num}")
+...
+Roll number of Joe is 20
+Roll number of Max is 25
+Roll number of Michel is 28
+>>>
+```
+
+## enumerate
+
+`enumerate()` is an amazing Built-in function offered by python. When used, gives us the index and the item combined. long story short! `enumerate` comes in handy while working with loops as it gives us access to both the item and it's index at the same time.
+
+### Syntax
+
+`enumerate(iterable, start=0)`
+
+### Parameters
+
+* Iterable: any iteration supporting object
+* Start: Starting index value, default is 0
+
+### Example 1: basic enumerate example
+
+```python
+>>> even_nums = [2, 4, 6, 8, 10, 12]
+print(list(enumerate(even_nums)))
+>>> 
+[(0, 2), (1, 4), (2, 6), (3, 8), (4, 10), (5, 12)]
+>>>
+```
+
+Now before we use it in a loop let's take a look how we would do the same thing in a traditional way.
+
+### Example 2: looping without `enumerate()`
+
+```python
+>>> even_nums = [2, 4, 6, 8, 10, 12]
+>>> for index in range(0,  len(even_nums)):
+...     print(f"Index of {even_nums[index]} is {index}")
+...
+Index of 2 is 0
+Index of 4 is 1
+Index of 6 is 2
+Index of 8 is 3
+Index of 10 is 4
+Index of 12 is 5
+>>>
+```
+
+### Example 3: looping with `enumerate()`
+
+```python
+>>> even_nums = [2, 4, 6, 8, 10, 12]
+>>> for index, item in enumerate(even_nums):
+...     print(f"Index of {item} is {index}")
+...
+Index of 2 is 0
+Index of 4 is 1
+Index of 6 is 2
+Index of 8 is 3
+Index of 10 is 4
+Index of 12 is 5
+>>>
+```
+
+[comment]: # (Zip and Enumerarate by Tushar ends here)
 
 ***