Python offers several different methods for opening text files, but are all options equally good? What’s the best method for the generic case of opening a text file?
The most basic is the following:
# Open the file
f = open('file.txt', 'r')
The r
means that the file is being opened as read-only. The other options are w
for write-only, a
for append-only, and r+
for both reading and writing. If you use r+
, you could accidentally write over your file, so it is best to use r
unless you specifically want to edit the file.
From there, you can read the file with:
# Read the file
f.read()
'Hello World'
It’s important to always close files after you’re done reading them, so the entire code should look like:
# Open the file
f = open('file.txt', 'r')
# Read the file
print(f.read())
# Do other things with the file
#Close the file
f.close()
Hello World
The problem with this is that if something happens in your code which interrupts the program, it will abort before it closes your file. What you can do to avoid this is to use a try
/finally
statement. This way you try
a section, and if there’s a bug it will end the try
section but still complete the finally
section, so you can be guaranteed that the file will be closed properly.
# Open the file
f = open('file.txt', 'r')
try:
# Read the file
print(f.read())
# Do other things with the file
finally:
#Close the file
f.close()
Hello World
However, there’s an easier way to do this, and that’s using the with
statement. This is a simple and safe way to open a file.
# Use a with statement
with open('file.txt') as f:
# Read the file
print(f.read())
# Do other things with the file
Hello World
Whenever the with
statement ends, the file will be properly closed.
pathlib
also offers another way to open and read files. It’s simple, safe, and can be done with a one-liner. It’s my go-to way of reading files.
from pathlib import Path
Path('file.txt').read_text()
'Hello World'