Environment data

VS Code version: 1.20
Python Extension version: 2018.1.0
Python Version: 3.6
OS and version: MacOS Sierra 0.12.6

Actual behavior

First file save with python code formats it to default yapf style. Second save format code to intended, custom style specified in .style.yapf.

To fix this issue added custom argument to workspace settings:

    "python.formatting.yapfArgs": [
        "--style=.style.yapf"
    ]

After that yapf on save works as intended

Expected behavior

After changes in code and saving file, yapf should format code to style described in .style.yapf

Steps to reproduce:

• open project
• install and enable yapf
• enable format on save
• create .style.yapf file with custom settings (SPLIT_BEFORE_FIRST_ARGUMENT = true)
• add changes to any .py file
• save
• now file is formatted with default style
• add changes to same file
• save
• now file is formatted with custom style