Exceptions
Exceptions
In Python, exceptions are a way to handle unexpected or exceptional situations in your code. When a Python script encounters an error during its execution, it raises an exception. Handling these exceptions allows you to gracefully manage errors and prevent your program from crashing.
Here's a basic overview of exceptions in Python:
### 1. Raising an Exception:
You can raise an exception explicitly using the `raise` keyword. For example:
```python
x = 10
if x > 5:
raise Exception("x should not be greater than 5")
```
### 2. Built-in Exceptions:
Python has many built-in exceptions like `TypeError`, `ValueError`, and `ZeroDivisionError`. You can catch these exceptions and handle them gracefully in your code.
### 3. Try-Except Blocks:
You can catch exceptions using `try` and `except` blocks. Code inside the `try` block is executed, and if an exception is raised, it is caught by an `except` block that handles the specific exception.
```python
try:
result = 10 / 0
except ZeroDivisionError:
print("Cannot divide by zero!")
```
You can also catch multiple exceptions or a generic exception:
```python
try:
# code that might raise an exception
except (TypeError, ValueError):
# handle multiple exceptions
except Exception as e:
# handle any other exceptions and access the exception object using 'e'
```
### 4. Finally Block:
You can use a `finally` block to specify code that will be executed regardless of whether an exception was raised or not.
```python
try:
# code that might raise an exception
except Exception:
# handle the exception
finally:
# this block will always be executed
```
### 5. Assertions:
Assertions are used to test if a condition is true. If it's false, the interpreter raises an `AssertionError` exception.
```python
x = 10
assert x > 0, "x should be greater than 0"
```
Remember that while exceptions are a powerful way to handle errors, it's important to handle them properly and provide meaningful error messages to aid in debugging.
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