# Python File I/O

Python has several functions for creating, reading, updating, and deleting files.

## Opening a File

The `open()` function is used to open a file. It takes two arguments: the file name and the mode.

There are four different modes for opening a file:

*   `"r"` - Read - Default value. Opens a file for reading, error if the file does not exist.
*   `"a"` - Append - Opens a file for appending, creates the file if it does not exist.
*   `"w"` - Write - Opens a file for writing, creates the file if it does not exist.
*   `"x"` - Create - Creates the specified file, returns an error if the file exists.

```python
f = open("demofile.txt", "r")
```

## Reading a File

The `read()` method is used to read the content of a file.

```python
f = open("demofile.txt", "r")
print(f.read())
```

## Writing to a File

The `write()` method is used to write to a file.

```python
f = open("demofile2.txt", "a")
f.write("Now the file has more content!")
f.close()
```

## Closing a File

It is a good practice to always close the file when you are done with it.

```python
f = open("demofile.txt", "r")
print(f.read())
f.close()
```

You can also use the `with` statement, which will automatically close the file for you.

```python
with open("demofile.txt", "r") as f:
  print(f.read())
```