YouTipPython3 File Writelines
# Python3.x Python3 File writelines() Method
[ Python3 File Methods](#)
* * *
`writelines()` is a method of file objects in Python, used to write a list of strings (or any iterable) to a file.
Unlike the [write()](#) method, `writelines()` can write multiple lines of content at once, but it does not automatically add newline characters.
To add newlines, you must specify the newline character `n`.
### Syntax
The syntax for the `writelines()` method is as follows:
fileObject.writelines( )
### Parameters
* **`fileObject`**: The file object, typically obtained by opening a file using the `open()` function.
* **`sequence`**: An iterable (such as a list, tuple, etc.), where each element must be a string.
* **Return Value**: No return value (returns `None`).
The `writelines()` method writes all strings from the iterable into the file sequentially. The position where writing occurs depends on the current file pointer position:
* If the file is opened in append mode (`"a"` or `"a+"`), the written content will be added to the end of the file.
* If the file is opened in read-write mode (`"r+"` or `"w+"`), the written content will overwrite existing content starting from the current file pointer position.
### Return Value
This method does not return a value.
### Example
The following example demonstrates the use of the `writelines()` method:
## Example
#!/usr/bin/python3
# Use the with statement to open the file, ensuring it is properly closed
with open("test.txt","w")as fo:
print("File name: ", fo.name)
seq =[" 1n"," 2"]
fo.writelines(seq)
The output of the above example is:
File name: test.txt
View file content:
$ cat test.txt 1 2
### Notes
1. **Does not automatically add newline characters**:
* `writelines()` does not automatically add a newline character at the end of each line. If you need newlines, you must explicitly add `n` in each string.
2. **File Mode**:
* If the file is opened in read-only mode (`"r"`), calling `writelines()` will raise an `io.UnsupportedOperation` exception.
* If the file is opened in write mode (`"w"` or `"w+"`), the file content will be cleared before writing new content.
* If the file is opened in append mode (`"a"` or `"a+"`), the written content will be added to the end of the file.
3. **File Pointer**:
* The write operation starts from the current file pointer position. If you need to write from the beginning of the file or a specific position, you can use the `seek()` method to move the file pointer.
4. **Iterable**:
* `sequence` can be any iterable (such as a list, tuple, generator, etc.), but each element within it must be a string.
* * Python3 File Methods](#)