cheetsheetz/python.md

# Python Cheat Sheet

## Variables and Data Types

### Variables

#### Declaring a variable
```
x = 5
```
#### Reassigning a variable
```
x = 10
```
### Data Types

#### Integer
```
x = 5
```
#### Float
```
x = 5.0
```

#### Boolean
```
x = True
```

#### String
```
x = "Hello, World!"
```

## Operators

#### Arithmetic Operators
```
+, -, *, /, %, **
```

#### Comparison Operators
```
==, !=, >, <, >=, <=
```

#### Logical Operators
```
and, or, not
```

## Control Structures

### Conditional Statements

#### If statement
```
if x > 5:
    print("x is greater than 5")
elif x == 5:
    print("x is equal to 5")
else:
    print("x is less than 5")
```
### Loops

#### For loop
```
for i in range(0, 5):
    print(i)
```

#### While loop
```
i = 0
while i < 5:
    print(i)
    i += 1
```

## Functions

#### Defining a function
```
def my_function(param1, param2):
    print(param1 + param2)
```
#### Calling a function
```
my_function(5, 10)
```

## Lists

#### Declaring a list
```
my_list = [1, 2, 3, 4, 5]
```
#### Accessing elements of a list
```
my_list[0]  # returns 1
my_list[-1] # returns 5
```

#### Slicing a list
```
my_list[1:3] # returns [2, 3]
```

#### Appending to a list
```
my_list.append(6)
```

#### Removing from a list
```
my_list.remove(2)
```

## Dictionaries

#### Declaring a dictionary
```
my_dict = {"key1": "value1", "key2": "value2"}
```

#### Accessing elements of a dictionary
```
my_dict["key1"]  # returns "value1"
```

#### Adding to a dictionary
```
my_dict["key3"] = "value3"
```

#### Removing from a dictionary
```
del my_dict["key2"]
```

## Classes

#### Declaring a class
```
class MyClass:
    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
```
my_instance = MyClass(5, 10)
```

#### Calling a method of a class
```
my_instance.my_method()
```

## Exceptions

#### Catching an exception
```
try:
    # some code that may raise an exception
except ExceptionType:
    # do something to handle the exception
```

#### Raising an exception
```
raise ExceptionType("Error message")
```