Clean up Python imports and add isort

.github/workflows/build-test.yaml

@@ -77,7 +77,7 @@ jobs:
           pip install -r py-polars/build.requirements.txt
       - name: Run formatting checks
         run: |
-          black --check .
+          cd py-polars && black --check . && isort --check . && cd ..
       - name: Run linting
         run: |
           cd py-polars && flake8 && cd ..

CONTRIBUTING.md

@@ -39,7 +39,7 @@ We use GitHub issues to track public bugs. Report a bug by [opening a new issue]
 We test the code formatting in the CI pipelines. If you don't want these to fail, you need to format:
 
 * **Rust** code with `$ cargo fmt`
-* **Python** code with [black (version 20.8b1)](https://github.com/psf/black), running `$ black .`
+* **Python** code with [black](https://github.com/psf/black) (version 21.6b0) and [isort](https://github.com/PyCQA/isort) (version 5.9.2). Run both from the `py-polars` directory with `$ black . && isort .`
 
 ## Linting
 We use linters to enforce code quality. This will be checked in CI.

py-polars/build.requirements.txt

@@ -1,8 +1,9 @@
 maturin==0.11.0
 pytest==5.3.1
-black==20.8b1
+black==21.6b0
+isort~=5.9.2
+mypy~=0.910
 numpy
 ghp-import
 pandas
 flake8
-mypy~=0.910

py-polars/legacy/pypolars/__init__.py

@@ -1,6 +1,7 @@
+import sys
+
 from polars import *
 from polars import __version__
-import sys
 
 print(
     "WARNING!\npy-polars was renamed to polars, please install polars!\nhttps://pypi.org/project/polars/",

py-polars/legacy/setup.py

@@ -1,6 +1,7 @@
-from setuptools import setup
 from os import path
 
+from setuptools import setup
+
 this_directory = path.abspath(path.dirname(__file__))
 with open(path.join(this_directory, "README.md"), encoding="utf-8") as f:
     long_description = f.read()

py-polars/polars/__init__.py

@@ -1,9 +1,9 @@
 # flake8: noqa
-from .series import Series, wrap_s
-from .frame import DataFrame, wrap_df, StringCache
+from .datatypes import *
+from .frame import DataFrame, StringCache, wrap_df
 from .functions import *
 from .lazy import *
-from .datatypes import *  # type: ignore
+from .series import Series, wrap_s
 
 # during docs building the binary code is not yet available
 try:

py-polars/polars/_html.py

@@ -1,22 +1,20 @@
 """
 Module for formatting output data in HTML.
 """
-
+import typing as tp
 from textwrap import dedent
 from types import TracebackType
-from typing import (
-    Dict,
-    Iterable,
-    List,
-    Optional,
-    Type,
-)
+from typing import Dict, Iterable, Optional, Type
+
 import polars as pl
 
 
 class Tag:
     def __init__(
-        self, elements: List[str], tag: str, attributes: Optional[Dict[str, str]] = None
+        self,
+        elements: tp.List[str],
+        tag: str,
+        attributes: Optional[Dict[str, str]] = None,
     ) -> None:
         self.tag = tag
         self.elements = elements
@@ -72,7 +70,7 @@ def div(inner: str) -> str:
 class HTMLFormatter:
     def __init__(self, df: "pl.DataFrame", max_cols: int = 75, max_rows: int = 40):
         self.df = df
-        self.elements: List[str] = []
+        self.elements: tp.List[str] = []
         self.max_cols = max_cols
         self.max_rows = max_rows
         self.row_idx: Iterable[int]
@@ -168,19 +166,11 @@ def write_style(self) -> None:
         template = dedent("\n".join((template_first, template_mid, template_last)))
         self.write(template)
 
-    def render(self) -> List[str]:  # type: ignore
+    def render(self) -> tp.List[str]:  # type: ignore
         """
         Return the lines needed to render a HTML table.
         """
         with Tag(self.elements, "div"):
             self.write_style()
             super().render()
         return self.elements
-
-
-if __name__ == "__main__":
-    df = pl.DataFrame({"a": [1, 2, 3], "b": [1, 2, 3]})
-
-    fmt = NotebookFormatter(df)
-
-    print("\n".join(fmt.render()))

py-polars/polars/datatypes.py

@@ -1,8 +1,9 @@
-from _ctypes import _SimpleCData
 import ctypes
-import typing
+import typing as tp
 from typing import Any, Dict, Type
 
+from _ctypes import _SimpleCData
+
 __pdoc__ = {
     "dtype_to_ctype": False,
     "dtype_to_int": False,
@@ -132,7 +133,7 @@ class Categorical(DataType):
 
 
 # Don't change the order of these!
-dtypes: typing.List[Type[DataType]] = [
+dtypes: tp.List[Type[DataType]] = [
     Int8,
     Int16,
     Int32,

py-polars/polars/ffi.py

@@ -1,9 +1,8 @@
-import numpy as np
-import numpy.core
-from numpy import ctypeslib
 import ctypes
 from typing import Any
 
+import numpy as np
+
 # https://stackoverflow.com/questions/4355524/getting-data-from-ctypes-array-into-numpy
 
 
@@ -26,7 +25,7 @@ def _ptr_to_numpy(ptr: int, len: int, ptr_type: Any) -> np.ndarray:
 
     """
     ptr_ctype = ctypes.cast(ptr, ctypes.POINTER(ptr_type))
-    return ctypeslib.as_array(ptr_ctype, (len,))
+    return np.ctypeslib.as_array(ptr_ctype, (len,))
 
 
 def _as_float_ndarray(ptr: int, size: int) -> np.ndarray: