1. Use Makefile and Python3 virtual env to install package.

2. Format python files in this plugion.

.gitignore

@@ -1,3 +1,4 @@
 *.pyc
 thirdparty/**
 config/**
+build/**

Makefile

@@ -0,0 +1,28 @@
+# Refer to davidhalter/jedi-vim.
+BUILD_VIRTUAL_ENV:=build/venv
+
+$(dir $(BUILD_VIRTUAL_ENV)):
+	mkdir -p $@
+
+$(BUILD_VIRTUAL_ENV): | $(dir $(BUILD_VIRTUAL_ENV))
+	python3 -m venv $@
+	# $|/bin/python -m pip upgrade
+
+$(BUILD_VIRTUAL_ENV)/bin/isort: | $(BUILD_VIRTUAL_ENV)
+	$|/bin/python -m pip install -q isort==4.3.21
+
+$(BUILD_VIRTUAL_ENV)/bin/yapf: | $(BUILD_VIRTUAL_ENV)
+	$|/bin/python -m pip install -q yapf==0.30.0
+
+isort: $(BUILD_VIRTUAL_ENV)/bin/isort
+	$(BUILD_VIRTUAL_ENV)/bin/isort --help
+
+yapf: $(BUILD_VIRTUAL_ENV)/bin/yapf
+	$(BUILD_VIRTUAL_ENV)/bin/yapf --help
+
+check: isort yapf
+
+clean:
+	rm -rf build
+
+.PHONY: check clean isort yapf

python/abstract_formatter.py

@@ -2,6 +2,7 @@
 import shutil
 import subprocess
 import tempfile
+
 import vim
 
 

python/format_json.py

@@ -1,10 +1,11 @@
-import sys
 import collections
 import json
+import sys
 
 if __name__ == "__main__":
     if len(sys.argv) != 3:
-        raise RuntimeError("Please call format_json.py with arugments: indent and filename.")
+        raise RuntimeError(
+            "Please call format_json.py with arugments: indent and filename.")
     indent = int(sys.argv[1])
     filename = sys.argv[2]
 

python/json_formatter.py

@@ -1,5 +1,4 @@
 import vim
-
 from abstract_formatter import AbstractFormatter
 
 

python/main.py

@@ -1,5 +1,4 @@
 import vim
-
 from json_formatter import JsonFormatter
 from python_formatter import PythonFormatter
 

python/python_formatter.py

@@ -1,5 +1,4 @@
 import vim
-
 from abstract_formatter import AbstractFormatter
 
 
@@ -17,6 +16,7 @@ def _getGuideFilename(self):
 
     def _getFormatCommand(self, formattedFilename, guideFilename):
         guideFilename = vim.eval("g:VimFormatterPythonStyle")
-        cmd = '{} --style="{}" "{}"'.format(self._yapf, guideFilename,
-                                            formattedFilename)
+        isort = "{}/build/venv/bin/isort".format(self._getRootDir())
+        cmd = '{} --stdout "{}" | {} --style="{}"'.format(
+            isort, formattedFilename, self._yapf, guideFilename)
         return cmd