[docs] Clarify parse_file takes file name not file object

[mdavis-xyz]

Problem

I'm new to pydantic.
I was reading the documentation about parse_file,

parse_file()
like parse_raw() but for files; cf. helper function

Based on this, I assumed you use it like:

with open('myfile.json', 'r') as f:
   MyModel.parse_file(f)

Which means you can use it with BytesIO or StringIO.

But that's not the case. It takes a file path, not a file-like object.

Solution

In the "Model Properties" section, change

parse_file()
like parse_raw() but for files; cf. helper function

to

parse_file()
like parse_raw() but for file paths; cf. helper function

In the helper function section, change

parse_file: this reads a file and passes the contents to parse_raw. If content_type is omitted, it is inferred from the file's extension.

to

parse_file: this takes in a file path and reads the file, then passes the contents to parse_raw. If content_type is omitted, it is inferred from the file's extension.

Then append to the code sample to provide an example of parse_file:

file_path = 'data.json'
with open(file_path, 'w') as f:
   f.write('{"id": 123, "name": "James"}')
m = user.parse_file(file_path)