`except` - Handling Errors
* Purpose: `except` is used within a `try...except` block to handle potential exceptions (errors) that might occur during the execution of code within the `try` block.
* Syntax:
```python
try:
# Code that might raise an exception
except ExceptionType:
# Code to handle the exception
```
* When to use: You use `except` when you want to gracefully handle situations where your code might encounter an error, preventing your program from crashing. Examples:
* File handling: Trying to open a file that doesn't exist.
* Network operations: Trying to connect to a server that's unavailable.
* Data validation: Trying to convert a string to an integer, but the string doesn't contain a valid number.
`for` - Looping
* Purpose: `for` is used to iterate over sequences (like lists, tuples, strings, dictionaries, etc.) and execute a block of code for each item in the sequence.
* Syntax:
```python
for item in sequence:
# Code to be executed for each item
```
* When to use: You use `for` when you need to process each element of a sequence. Examples:
* Printing a list:
```python
for item in my_list:
print(item)
```
* Calculating the sum of numbers in a list:
```python
total = 0
for number in my_numbers:
total += number
```
In summary:
* `except`: For handling errors and preventing program crashes.
* `for`: For looping through sequences and executing code for each item.
Let me know if you'd like to see more examples of how these keywords are used in practice!