How to reliably open a file in the same directory as a Python script

Michael Zippo

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I used to open files that were in the same directory as the currently running Python script by simply using a command like

open("Some file.txt", "r")

However, I discovered that when the script was run in Windows by double-clicking it, it would try to open the file from the wrong directory.

Since then I"ve used a command of the form

open(os.path.join(sys.path[0], "Some file.txt"), "r")

whenever I wanted to open a file. This works for my particular usage, but I"m not sure if sys.path[0] might fail in some other use case.

So my question is: What is the best and most reliable way to open a file that"s in the same directory as the currently running Python script?

Here"s what I"ve been able to figure out so far:

os.getcwd() and os.path.abspath("") return the "current working directory", not the script directory.
os.path.dirname(sys.argv[0]) and os.path.dirname(__file__) return the path used to call the script, which may be relative or even blank (if the script is in the cwd). Also, __file__ does not exist when the script is run in IDLE or PythonWin.
sys.path[0] and os.path.abspath(os.path.dirname(sys.argv[0])) seem to return the script directory. I"m not sure if there"s any difference between these two.

Edit:

I just realized that what I want to do would be better described as "open a file in the same directory as the containing module". In other words, if I import a module I wrote that"s in another directory, and that module opens a file, I want it to look for the file in the module"s directory. I don"t think anything I"ve found is able to do that...

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Boris Zelotti

Singapore | 2023-03-25

Simply put and clear. Thank you for sharing. How to reliably open a file in the same directory as a Python script and other issues with dirname was always my weak point 😁. I am just not quite sure it is the best method

Oliver Galleotti

Vigrinia | 2023-03-25

Maybe there are another answers? What How to reliably open a file in the same directory as a Python script exactly means?. Will get back tomorrow with feedback

Anna Ungerschaft

Berlin | 2023-03-25

Simply put and clear. Thank you for sharing. How to reliably open a file in the same directory as a Python script and other issues with getcwd was always my weak point 😁. I just hope that will not emerge anymore