Explain the concept of Python syntax and provide an example of a basic Python code structure.

Python Syntax:

Python syntax refers to the set of rules and conventions that dictate how Python code is written and structured. It defines how Python programs should be formatted to be both human-readable and interpretable by the Python interpreter. Python's syntax is known for its simplicity, clarity, and readability, making it an excellent choice for programmers, especially beginners.

Key Aspects of Python Syntax:

1. Indentation: Python uses whitespace (indentation) to indicate code blocks, such as loops and functions. This is different from many other programming languages that use braces or keywords like "end" to define blocks. For example:

```python
for i in range(5):
print("Hello, World!")
```

In this code, the indentation with four spaces signifies the code block inside the `for` loop.

2. Comments: Comments in Python begin with the `#` symbol and are used to add explanatory notes to the code. They are ignored by the Python interpreter. For example:

```python
# This is a comment
```

3. Variable Naming: Variable names are case-sensitive and can contain letters, numbers, and underscores. They must start with a letter or underscore, but not with a number. Examples: `my_variable`, `count`, `totalAmount`.

4. Statements: Python statements typically end with a newline character, and there's no need to use semicolons as in some other languages. For example:

```python
x = 5 # This is a statement
```

5. Whitespace: Python is sensitive to whitespace, so consistent indentation is crucial for code to be syntactically correct. Improper indentation can lead to errors.

Example of Basic Python Code Structure:

Here's an example of a basic Python code structure that demonstrates some of the key aspects of Python syntax:

```python
# This is a Python program that calculates the factorial of a number

# Function to calculate factorial
def factorial(n):
if n == 0:
return 1
else:
return n * factorial(n - 1)

# Input from the user
num = int(input("Enter a non-negative integer: "))

# Check for negative input
if num < 0:
print("Factorial is not defined for negative numbers.")
else:
result = factorial(num)
print(f"The factorial of {num} is {result}.")
```

In this example:

- Comments are used to explain the code.
- Indentation is used to define the code blocks within the `factorial` function and the `if-else` conditional statement.
- Variable naming follows the conventions, such as `num` and `result`.
- Statements are used to assign values to variables and print output.

This example showcases the readability and simplicity of Python syntax, making it accessible for both beginners and experienced programmers. Python's syntax encourages clean and concise code that is easy to understand and maintain.