feature/142: drop support for python3.5 (#272)

* drop support and ci for python=3.5

* update environment.yml and requirements.txt

* update travis config

* update travis config

* update travis config

* remove autopep8

* fix pylint error, remove io import in __init__

* add test for DataFrameSchema.to_script

* fix to_script tests

* ignore test on windows

.travis.yml

@@ -16,11 +16,9 @@ os:
   - windows
 
 env:
-  - JOB="3.5" ENV_FILE="ci/deps/env_35.yml"
-  - JOB="3.6" ENV_FILE="ci/deps/env_36.yml"
-  - JOB="3.7" ENV_FILE="ci/deps/env_37.yml"
-  - JOB="3.8" ENV_FILE="ci/deps/env_38.yml"
-  - JOB="latest" ENV_FILE="ci/deps/env_latest.yml"
+  - PYTHON_VERSION=3.6
+  - PYTHON_VERSION=3.7
+  - PYTHON_VERSION=3.8
 
 before_install:
   - |
@@ -70,7 +68,8 @@ install:
     conda info -a || exit 1
   # Setup Conda Env
   - |
-    conda env create -n hosts -f $ENV_FILE || exit 1
+    conda create -n hosts python=$PYTHON_VERSION || exit 1
+    conda env update -n hosts -f environment.yml
     source activate hosts
 
     python setup.py install

docs/source/schema_inference.rst

@@ -83,11 +83,9 @@ You can also write your schema to a python script with :py:func:`io.to_script`:
 .. testcode:: infer_dataframe_schema
    :skipif: SKIP
 
-   from pandera import io
-
    # supply a file-like object, Path, or str to write to a file. If not
    # specified, to_script will output the code as a string.
-   schema_script = io.to_script(schema)
+   schema_script = schema.to_script()
    print(schema_script)
 
 .. testoutput:: infer_dataframe_schema

environment.yml

@@ -1,11 +1,8 @@
-name: pandera-dev-latest
+name: pandera-dev
 channels:
   - defaults
   - conda-forge
 dependencies:
-  # required
-  - python
-
   # environment management
   - pip
 
@@ -27,7 +24,7 @@ dependencies:
   - asv
 
   # optional
-  - pre-commit
+  - pre_commit
 
   # pandera dependencies
   - black
@@ -38,4 +35,4 @@ dependencies:
   - pyyaml
 
   - pip:
-    - sphinx_autodoc_typehints==1.10.3
+    - sphinx_autodoc_typehints

pandera/__init__.py

@@ -1,6 +1,6 @@
 """A flexible and expressive pandas validation library."""
 
-from . import errors, constants, io
+from . import errors, constants
 from .checks import Check
 from .hypotheses import Hypothesis
 from .decorators import check_input, check_output
@@ -11,7 +11,6 @@
 from .version import __version__
 
 
-# pylint: disable=invalid-name
 Bool = PandasDtype.Bool
 DateTime = PandasDtype.DateTime
 Category = PandasDtype.Category

pandera/checks.py

@@ -218,12 +218,11 @@ def statistics(self, statistics):
         """Set check statistics."""
         self._statistics = statistics
 
+    @staticmethod
     def _format_groupby_input(
-            self,
             groupby_obj: GroupbyObject,
             groups: Optional[List[str]],
     ) -> Union[Dict[str, Union[pd.Series, pd.DataFrame]]]:
-        # pylint: disable=no-self-use
         """Format groupby object into dict of groups to Series or DataFrame.
 
         :param groupby_obj: a pandas groupby object.

pandera/dtypes.py

@@ -236,7 +236,7 @@ def from_python_type(cls, python_type: type) -> "PandasDtype":
         return pandas_dtype
 
     def __eq__(self, other):
-        # pylint: disable=comparison-with-callable,too-many-return-statements
+        # pylint: disable=comparison-with-callable
         # see https://github.com/PyCQA/pylint/issues/2306
         if other is None:
             return False

pandera/io.py

@@ -1,10 +1,10 @@
 """Module for reading and writing schema objects."""
 
-import yaml
 from functools import partial
 from pathlib import Path
 
 import pandas as pd
+import yaml
 
 from .dtypes import PandasDtype
 from .schema_statistics import get_dataframe_schema_statistics
@@ -65,7 +65,7 @@ def _serialize_component_stats(component_stats):
 
 def _serialize_schema(dataframe_schema):
     """Serialize dataframe schema into into json/yaml-compatible format."""
-    from pandera import __version__  # pylint: disable-all
+    from pandera import __version__  # pylint: disable=import-outside-toplevel
 
     statistics = get_dataframe_schema_statistics(dataframe_schema)
 
@@ -114,8 +114,7 @@ def handle_stat_dtype(stat):
 
 
 def _deserialize_component_stats(serialized_component_stats):
-    # pylint: disable-all
-    from pandera import Check
+    from pandera import Check  # pylint: disable=import-outside-toplevel
 
     pandas_dtype = PandasDtype.from_str_alias(
         serialized_component_stats["pandas_dtype"]
@@ -142,7 +141,7 @@ def _deserialize_component_stats(serialized_component_stats):
 
 
 def _deserialize_schema(serialized_schema):
-    # pylint: disable-all
+    # pylint: disable=import-outside-toplevel
     from pandera import DataFrameSchema, Column, Index, MultiIndex
 
     columns, index = None, None
@@ -168,10 +167,7 @@ def _deserialize_schema(serialized_schema):
         ])
 
     return DataFrameSchema(
-        columns={
-            col_name: column
-            for col_name, column in columns.items()
-        },
+        columns=columns,
         index=index,
         coerce=serialized_schema["coerce"],
         strict=serialized_schema["strict"],
@@ -290,18 +286,10 @@ def _format_index(index_statistics):
 
 
 def _format_script(script):
-    try:
-        import black
-        formatter = partial(
-            black.format_str, mode=black.FileMode(line_length=80)
-        )
-    except ImportError:
-        # use autopep8 for python3.5
-        import autopep8
-        formatter = partial(
-            autopep8.fix_code, options={"aggressive": 1}
-        )
-
+    import black  # pylint: disable=import-outside-toplevel
+    formatter = partial(
+        black.format_str, mode=black.FileMode(line_length=80)
+    )
     return formatter(script)
 
 
@@ -356,15 +344,3 @@ def to_script(dataframe_schema, path_or_buf=None):
 
     with Path(path_or_buf).open("w") as f:
         f.write(formatted_script)
-
-    def _write_script(obj, stream):
-        try:
-            return yaml.safe_dump(obj, stream=stream, sort_keys=False)
-        except TypeError:
-            return yaml.safe_dump(obj, stream=stream)
-
-    try:
-        with Path(path_or_buf).open("w") as f:
-            _write_script(formatted_script, f)
-    except (TypeError, OSError):
-        return _write_script(formatted_script, path_or_buf)