# Python Try Except

The `try` block lets you test a block of code for errors. The `except` block lets you handle the error. The `else` block lets you execute code when there is no error. The `finally` block lets you execute code, regardless of the result of the try- and except blocks.

## Exception Handling

When an error occurs, or exception as we call it, Python will normally stop and generate an error message.

These exceptions can be handled using the `try` statement:

```python
try:
  print(x)
except:
  print("An exception occurred")
```

## Many Exceptions

You can define as many exception blocks as you want, e.g. if you want to execute a special block of code for a special kind of error:

```python
try:
  print(x)
except NameError:
  print("Variable x is not defined")
except:
  print("Something else went wrong")
```

## Else

You can use the `else` keyword to define a block of code to be executed if no errors were raised:

```python
try:
  print("Hello")
except:
  print("Something went wrong")
else:
  print("Nothing went wrong")
```

## Finally

The `finally` block, if specified, will be executed regardless if the `try` block raises an error or not.

```python
try:
  print(x)
except:
  print("Something went wrong")
finally:
  print("The 'try except' is finished")
```

## Raise an Exception

As a Python developer you can choose to throw an exception if a condition occurs.

To throw (or raise) an exception, use the `raise` keyword.

```python
x = -1

if x < 0:
  raise Exception("Sorry, no numbers below zero")
```

[[programming/python/python]]