Reworked Python sheet for new format.

python.md

@@ -1,180 +1,218 @@
 # Python Cheat Sheet
 
-## Variables and Data Types
+## Table of Contents
 
-### Variables
+1. [Variables](#variables)
+2. [Data Types](#data-types)
+3. [Operators](#operators)
+4. [Control Structures](#control-structures)
+5. [Functions](#functions)
+6. [Lists](#lists)
+7. [Strings](#strings)
+8. [Dictionaries](#dictionaries)
+9. [Tuples](#tuples)
+10. [Sets](#sets)
+11. [File Handling](#file-handling)
+12. [Exception Handling](#exception-handling)
+13. [Classes and Objects](#classes-and-objects)
 
-#### Declaring a variable
+## Variables
-```
-x = 5
-```
-#### Reassigning a variable
-```
-x = 10
-```
-### Data Types
 
-#### Integer
+### Declaration and Assignment
-```
+```python
-x = 5
+variable_name = value
-```
-#### Float
-```
-x = 5.0
 ```
 
-#### Boolean
+### Variable Types
-```
+- String: `string_variable = "Hello"`
-x = True
+- Integer: `int_variable = 42`
-```
+- Float: `float_variable = 3.14`
+- Boolean: `bool_variable = True`
 
-#### String
+## Data Types
-```
+
-x = "Hello, World!"
+### Basic Types
-```
+- String
+- Integer
+- Float
+- Boolean
+
+### Compound Types
+- List
+- Tuple
+- Set
+- Dictionary
 
 ## Operators
 
-#### Arithmetic Operators
+### Arithmetic Operators
-```
+```python
-+, -, *, /, %, **
++, -, *, /, %, ** (exponentiation), //
 ```
 
-#### Comparison Operators
+### Comparison Operators
-```
+```python
-==, !=, >, <, >=, <=
+==, !=, <, >, <=, >=
 ```
 
-#### Logical Operators
+### Logical Operators
-```
+```python
 and, or, not
 ```
 
+### Assignment Operators
+```python
+=, +=, -=, *=, /=, %=
+```
+
 ## Control Structures
 
-### Conditional Statements
+### If Statement
-
+```python
-#### If statement
+if condition:
-```
+    # code to be executed if the condition is true
-if x > 5:
+elif another_condition:
-    print("x is greater than 5")
+    # code to be executed if the previous condition was false and this one is true
-elif x == 5:
-    print("x is equal to 5")
 else:
-    print("x is less than 5")
+    # code to be executed if all conditions are false
-```
-### Loops
-
-#### For loop
-```
-for i in range(0, 5):
-    print(i)
 ```
 
-#### While loop
+### For Loop
+```python
+for i in range(5):
+    # code to be executed in each iteration
 ```
-i = 0
+
-while i < 5:
+### While Loop
-    print(i)
+```python
-    i += 1
+while condition:
+    # code to be executed as long as the condition is true
 ```
 
 ## Functions
 
-#### Defining a function
+### Function Declaration
+```python
+def function_name(param1, param2):
+    # code to be executed
+    return result  # optional
 ```
-def my_function(param1, param2):
+
-    print(param1 + param2)
+### Function Call
-```
+```python
-#### Calling a function
+result = function_name(arg1, arg2)
-```
-my_function(5, 10)
 ```
 
 ## Lists
 
-#### Declaring a list
+### List Declaration
-```
+```python
-my_list = [1, 2, 3, 4, 5]
+my_list = [1, 2, 3, "hello", True]
-```
-#### Accessing elements of a list
-```
-my_list[0]  # returns 1
-my_list[-1] # returns 5
 ```
 
-#### Slicing a list
+### List Operations
-```
+```python
-my_list[1:3] # returns [2, 3]
+my_list.append(4)  # Add an element to the end
+my_list.remove("hello")  # Remove a specific element
 ```
 
-#### Appending to a list
+## Strings
-```
+
-my_list.append(6)
+### String Concatenation
+```python
+string1 = "Hello"
+string2 = "World"
+concatenated = string1 + " " + string2
 ```
 
-#### Removing from a list
+### String Methods
-```
+```python
-my_list.remove(2)
+len(my_string)  # Length of the string
+my_string.find("find")  # Index of the first occurrence of "find"
+my_string.split(",")  # Split the string into a list
 ```
 
 ## Dictionaries
 
-#### Declaring a dictionary
+### Dictionary Declaration
-```
+```python
 my_dict = {"key1": "value1", "key2": "value2"}
 ```
 
-#### Accessing elements of a dictionary
+### Dictionary Operations
-```
+```python
-my_dict["key1"]  # returns "value1"
+my_dict["new_key"] = "new_value"  # Add a new key-value pair
+del my_dict["key1"]  # Remove a key-value pair
 ```
 
-#### Adding to a dictionary
+## Tuples
-```
+
-my_dict["key3"] = "value3"
+### Tuple Declaration
+```python
+my_tuple = (1, 2, 3, "hello", True)
 ```
 
-#### Removing from a dictionary
+### Immutable Nature
-```
+```python
-del my_dict["key2"]
+# Tuple elements cannot be changed once set
+my_tuple[0] = 4  # This will result in an error
 ```
 
-## Classes
+## Sets
 
-#### Declaring a class
+### Set Declaration
-```
+```python
-class MyClass:
+my_set = {1, 2, 3, 3, 4}
-    def __init__(self, param1, param2):
-        self.param1 = param1
-        self.param2 = param2
-    
-    def my_method(self):
-        print(self.param1 + self.param2)
 ```
 
-#### Creating an instance of a class
+### Set Operations
-```
+```python
-my_instance = MyClass(5, 10)
+my_set.add(5)  # Add an element to the set
+my_set.remove(3)  # Remove an element from the set
 ```
 
-#### Calling a method of a class
+## File Handling
-```
+
-my_instance.my_method()
+### Reading from a File
+```python
+with open("filename.txt", "r") as file:
+    file_content = file.read()
 ```
 
-## Exceptions
+### Writing to a File
-
+```python
-#### Catching an exception
+with open("filename.txt", "w") as file:
+    file.write("Hello, World!")
 ```
+
+## Exception Handling
+
+### Try-Except Block
+```python
 try:
-    # some code that may raise an exception
+    # code that may raise an exception
-except ExceptionType:
+except Exception as e:
-    # do something to handle the exception
+    # handle the exception
+    print("Error:", e)
+```
+
+## Classes and Objects
+
+### Class Declaration
+```python
+class MyClass:
+    def __init__(self, name):
+        self.name = name
+
+    def say_hello(self):
+        print(f"Hello, {self.name}!")
+```
+
+### Object Instantiation
+```python
+obj = MyClass("John")
+obj.say_hello()  # Outputs: Hello, John!
 ```
 
-#### Raising an exception
-```
-raise ExceptionType("Error message")
 ```