A for loop is a way to repeat a block of code multiple times. It allows us to perform a set of instructions for each item in a sequence, such as a list or a string.
Here's the basic structure of a for loop:
```python [main.nopy]
for item in sequence:
# code to be executed
```
Let's break it down:
- `for` is a keyword that tells Python we want to start a for loop.
- `item` is a variable that represents each item in the sequence. You can choose any name you like for this variable.
- `sequence` is the collection of items over which the loop will iterate. It can be a list, string, tuple, or any other iterable object.
- The colon `:` at the end of the line indicates the start of the loop block.
- The indented code below the `for` statement is the body of the loop. It will be executed for each item in the sequence.
Here's an example that demonstrates how a for loop works:
fruits = ["apple", "banana", "orange"]
for fruit in fruits:
print(fruit)apple banana orange
In this example, we have a list of fruits. The for loop iterates over each fruit in the list and prints it. Click the run button to see the output. You should get: ``` apple banana orange ``` The loop starts with the first item in the list (`"apple"`), executes the code inside the loop block (printing the fruit), and then moves to the next item (`"banana"`) and repeats the process until all items have been processed. You can use for loops to perform various operations, such as calculating sums, counting occurrences, or modifying elements in a sequence. Remember, indentation is crucial in Python. Make sure to indent the code inside the loop block consistently to indicate that it belongs to the loop. If you want to skip an item or break out of the loop early when a certain condition is met, you will need to learn about the [continue and break](/tutorials/continue-break) statements.