Add a couple of exercises

Author: abregman

README.md

@@ -39,9 +39,18 @@
 |Name|Objective & Instructions|Solution|Comments|
 |--------|--------|------|----|
 | 22 times | [Exercise](exercises/hello_world/22_times.md) | | |
+| What is the result? | [Exercise](exercises/strings/what_is_the_result.md) | [Solution](solutions/strings/what_is_the_result.md) | |
 | Starts with a letter | [Exercise](exercises/strings/letter_start.md) | [Solution](solutions/strings/letter_start.md) | |
 | All Digits | [Exercise](exercises/strings/all_digits.md) | [Solution](solutions/strings/all_digits.md) | |
 | Removing Characters | [Exercise](exercises/strings/removing_characters.md) | [Solution](solutions/strings/removing_characters.md) | |
+| Reverse a String | [Exercise](exercises/strings/reverse_string.md) | [Solution](solutions/strings/reverse_string.md) | |
+| Compress Strings | [Exercise](exercises/strings/compress_strings.md) | | |
+
+## Numbers
+
+|Name|Objective & Instructions|Solution|Comments|
+|--------|--------|------|----|
+| Palindrome | [Exercise](exercises/numbers/palindrome.md) | [Solution](solutions/numbers/palindrome.md) | |
 
 ## Lists
 
@@ -50,6 +59,9 @@
 | Access List Items | [Exercise](exercises/hello_world/access_list_items.md) | [Solution](solutions/hello_world/access_list_items.md) | |
 | Equal Lists | [Exercise](exercises/lists/equal_lists.md) | [Solution](solutions/lists/equal_lists.md) | |
 | Length | [Exercise](exercises/hello_world/length.md) | | |
+| Min Max | [Exercise](exercises/lists/min_max.md) | [Solution](solutions/lists/min_max.md) | |
+| Three Biggest Items | [Exercise](exercises/lists/three_biggest_items.md) | [Solution](solutions/lists/three_biggest_items.md) | |
+| What is the result? | [Exercise](exercises/lists/what_is_the_result.md) | [Solution](solutions/lists/what_is_the_result.md) | |
 
 ## Loops
 
@@ -61,7 +73,9 @@
 
 |Name|Objective & Instructions|Solution|Comments|
 |--------|--------|------|----|
+| My First Function | [Exercise](exercises/functions/my_first_function.md) | [Solution](solutions/functions/my_first_function.md) | |
 | Calculator | [Exercise](exercises/functions/calculator.md) | [Solution](solutions/functions/calculator.md) | |
+| First Class Objects | [Exercise](exercises/functions/first_class_objects.md) | [Solution](solutions/functions/first_class_objects.md) | |
 
 ## Magic Methods
 
@@ -104,6 +118,12 @@
 | File exists | [Exercise](exercises/os/file_exists.md) | | |
 | Print all the files in a directory | [Exercise](exercises/os/print_all_files_in_dir.md) | | |
 
+## Improve the Code
+
+|Name|Objective & Instructions|Solution|Comments|
+|--------|--------|------|----|
+| Vowel Letters | [Exercise](exercises/improve_the_code/vowel_letters.md) | [Solution](solutions/improve_the_code/vowel_letters.md) | |
+
 ## Misc
 
 |Name|Objective & Instructions|Solution|Comments|

exercises/functions/first_class_objects.md

@@ -0,0 +1,3 @@
+## First Class Objects
+
+1. In Python, functions are first-class objects. What does it mean?

exercises/functions/my_first_function.md

@@ -0,0 +1,3 @@
+## My First Function
+
+1. Write a function to print "Hello World"

exercises/improve_the_code/vowel_letters.md

@@ -0,0 +1,9 @@
+## Vowel Letters
+
+1. Improve the following code
+
+```python
+char = input("Insert a character: ")
+if char == "a" or char == "o" or char == "e" or char =="u" or char == "i":
+    print("It's a vowel!")
+```

exercises/lists/min_max.md

@@ -0,0 +1,3 @@
+## Lists - Min Max
+
+How do you get the maximum and minimum values from a list?

exercises/lists/three_biggest_items.md

@@ -0,0 +1,3 @@
+## Three Biggest Items
+
+1. Print three biggest items of a list

exercises/numbers/palindrome.md

@@ -0,0 +1,3 @@
+## Palindrome
+
+1. Write code that determines if a number is a Palindrome

exercises/strings/compress_strings.md

@@ -0,0 +1,8 @@
+## Compress Strings
+
+1. Write code that compresses a string
+  - 'aaaabbccc' -> 'a4b2c3'
+  - 'abbbc' -> 'a1b3c1'
+2. Write code that decompresses a string
+  - 'a4b2c3' -> 'aaaabbccc'
+  - 'a1b3c1' -> 'abbbc'

exercises/strings/reverse_string.md

@@ -0,0 +1,3 @@
+## Reverse String
+
+1. Reverse a string

exercises/strings/what_is_the_result.md

@@ -0,0 +1,9 @@
+## What is the result?
+
+1. What is the result of each of the following statements?
+
+- "abc"*3
+- "abc"*2.5
+- "abc"*2.0
+- "abc"*True
+- "abc"*False

solutions/functions/first_class_objects.md

@@ -0,0 +1,15 @@
+## First Class Objects
+
+1. In Python, functions are first-class objects. What does it mean?
+
+### Solution
+
+In general, first class objects in programming languages are objects which can be assigned to variable, used as a return value and can be used as arguments or parameters.<br>
+In python you can treat functions this way. Let's say we have the following function
+
+```
+def my_function():
+    return 5
+```
+
+You can then assign a function to a variables like this `x = my_function` or you can return functions as return values like this `return my_function`

solutions/functions/my_first_function.md

@@ -0,0 +1,10 @@
+## My First Function
+
+1. Write a function to print "Hello World"
+
+### Solution
+
+```python
+def print_hello_world():
+    print("hello world")
+```

solutions/improve_the_code/vowel_letters.md

@@ -0,0 +1,22 @@
+## Vowel Letters
+
+1. Improve the following code
+
+```python
+char = input("Insert a character: ")
+if char == "a" or char == "o" or char == "e" or char =="u" or char == "i":
+    print("It's a vowel!")
+```
+
+### Solution
+
+```python
+char = input("Insert a character: ") # For readablity
+if lower(char[0]) in "aieou": # Takes care of multiple characters and separate cases
+    print("It's a vowel!")
+```
+OR
+```python
+if lower(input("Insert a character: ")[0]) in "aieou": # Takes care of multiple characters and small/Capital cases
+    print("It's a vowel!")
+```

solutions/lists/min_max.md

@@ -0,0 +1,8 @@
+## Lists - Min Max
+
+How do you get the maximum and minimum values from a list?
+
+### Solution
+
+Maximum: max(some_list)
+Minimum: min(some_list)

solutions/lists/three_biggest_items.md

@@ -0,0 +1,16 @@
+## Three Biggest Items
+
+1. Print three biggest items of a list
+
+### Solution
+
+```python
+sorted(some_list, reverse=True)[:3]
+```
+
+Or
+
+```python
+some_list.sort(reverse=True)
+some_list[:3]
+```

solutions/lists/what_is_the_result.md

@@ -0,0 +1,19 @@
+## What is the result?
+
+1. What is the result of the following block of code?
+
+```python
+x = ['a', 'b', 'c']
+for i in x:
+    if i == 'b':
+        x = ['z', 'y']
+    print(i)
+```
+
+### Solution
+
+```
+a
+b
+c
+```

solutions/numbers/palindrome.md

@@ -0,0 +1,31 @@
+## Palindrome
+
+1. Write code that determines if a number is a Palindrome
+
+## Solution
+
+1.
+
+```
+from typing import Union
+
+def isNumberPalindrome(number: Union[int, str]) -> bool:
+    if isinstance(number, int):
+        number = str(number)
+    return number == number[::-1]
+
+print(isNumberPalindrome("12321"))
+```
+
+- Using Python3.10 that accepts using bitwise operator '|'.
+
+```
+def isNumberPalindrome(number: int | str) -> bool:
+    if isinstance(number, int):
+        number = str(number)
+    return number == number[::-1]
+
+print(isNumberPalindrome("12321"))
+```
+
+Note: Using slicing to reverse a list could be slower than other options like `reversed` that return an iterator.

solutions/strings/reverse_string.md

@@ -0,0 +1,20 @@
+## Reverse String
+
+1. Reverse a string
+
+### Solution
+
+```
+my_string[::-1]
+```
+
+A more visual way is:<br>
+<i>Careful: this is very slow</i>
+
+```
+def reverse_string(string):
+    temp = ""
+    for char in string:
+        temp =  char + temp
+    return temp
+```

solutions/strings/what_is_the_result.md

@@ -0,0 +1,17 @@
+## What is the result?
+
+1. What is the result of each of the following statements?
+
+- "abc"*3
+- "abc"*2.5
+- "abc"*2.0
+- "abc"*True
+- "abc"*False
+
+### Solution
+
+* abcabcabc
+* TypeError
+* TypeError
+* "abc"
+* ""