[python] Does reading an entire file leave the file handle open?

If you read an entire file with content = open('Path/to/file', 'r').read() is the file handle left open until the script exits? Is there a more concise method to read a whole file?

You can use pathlib.

For Python 3.5 and above:

from pathlib import Path
contents = Path(file_path).read_text()

For older versions of Python use pathlib2:

$ pip install pathlib2

Then:

from pathlib2 import Path
contents = Path(file_path).read_text()

This is the actual read_text implementation:

def read_text(self, encoding=None, errors=None):
    """
    Open the file in text mode, read it, and close the file.
    """
    with self.open(mode='r', encoding=encoding, errors=errors) as f:
        return f.read()

Instead of retrieving the file content as a single string, it can be handy to store the content as a list of all lines the file comprises:

with open('Path/to/file', 'r') as content_file:
    content_list = content_file.read().strip().split("\n")

As can be seen, one needs to add the concatenated methods .strip().split("\n") to the main answer in this thread.

Here, .strip() just removes whitespace and newline characters at the endings of the entire file string, and .split("\n") produces the actual list via splitting the entire file string at every newline character \n.

Moreover, this way the entire file content can be stored in a variable, which might be desired in some cases, instead of looping over the file line by line as pointed out in this previous answer.

Well, if you have to read file line by line to work with each line, you can use

with open('Path/to/file', 'r') as f:
    s = f.readline()
    while s:
        # do whatever you want to
        s = f.readline()

Or even better way:

with open('Path/to/file') as f:
    for line in f:
        # do whatever you want to