Merge pull request #50 from sarugaku/feature/48

Provide a way to capture or wrap streams

.travis.yml

@@ -11,7 +11,7 @@ install:
   - "pipenv install --dev"
   - "pipenv run pip install --upgrade -e .[spinner,tests]"
 script:
-    - "pipenv run pytest -v -n auto tests/"
+    - "pipenv run pytest -v tests/"
 
 jobs:
   include:
@@ -33,7 +33,7 @@ jobs:
     - stage: coverage
       python: "3.6"
       install:
-        - "pip install --upgrade pip pipenv pytest-cov pytest-xdist pytest-timeout pytest"
+        - "pip install --upgrade pip pipenv pytest-cov pytest-timeout pytest"
         - "pipenv install --dev"
       script:
-        - "pipenv run pytest -n auto --timeout 300 --cov=vistir --cov-report=term-missing --cov-report=xml --cov-report=html tests"
+        - "pipenv run pytest --timeout 300 --cov=vistir --cov-report=term-missing --cov-report=xml --cov-report=html tests"

README.rst

@@ -131,6 +131,7 @@ default encoding:
     * ``vistir.contextmanagers.atomic_open_for_write``
     * ``vistir.contextmanagers.cd``
     * ``vistir.contextmanagers.open_file``
+    * ``vistir.contextmanagers.replaced_stream``
     * ``vistir.contextmanagers.spinner``
     * ``vistir.contextmanagers.temp_environ``
     * ``vistir.contextmanagers.temp_path``
@@ -203,6 +204,23 @@ to pair this with an iterator which employs a sensible chunk size.
             shutil.copyfileobj(fp, filecontents)
 
 
+.. _`replaced_stream`:
+
+A context manager to temporarily swap out *stream_name* with a stream wrapper.  This will
+capture the stream output and prevent it from being written as normal.
+
+.. code-block:: python
+
+    >>> orig_stdout = sys.stdout
+    >>> with replaced_stream("stdout") as stdout:
+    ...     sys.stdout.write("hello")
+    ...     assert stdout.getvalue() == "hello"
+    ...     assert orig_stdout.getvalue() != "hello"
+
+    >>> sys.stdout.write("hello")
+    'hello'
+
+
 .. _`spinner`:
 
 **spinner**
@@ -286,8 +304,13 @@ The following Miscellaneous utilities are available as helper methods:
     * ``vistir.misc.partialclass``
     * ``vistir.misc.to_text``
     * ``vistir.misc.to_bytes``
+    * ``vistir.misc.divide``
+    * ``vistir.misc.take``
+    * ``vistir.misc.chunked``
     * ``vistir.misc.decode_for_output``
-
+    * ``vistir.misc.get_canonical_encoding_name``
+    * ``vistir.misc.get_wrapped_stream``
+    * ``vistir.misc.StreamWrapper``
 
 .. _`shell_escape`:
 
@@ -401,6 +424,62 @@ Converts arbitrary byte-convertable input to bytes while handling errors.
     b'this is some text'
 
 
+.. _`chunked`:
+
+**chunked**
+////////////
+
+Splits an iterable up into groups *of the specified length*, per `more itertools`_.  Returns an iterable.
+
+This example will create groups of chunk size **5**, which means there will be *6 groups*.
+
+.. code-block:: python
+
+    >>> chunked_iterable = vistir.misc.chunked(5, range(30))
+    >>> for chunk in chunked_iterable:
+    ...     add_to_some_queue(chunk)
+
+.. _more itertools: https://more-itertools.readthedocs.io/en/latest/api.html#grouping
+
+
+.. _`take`:
+
+**take**
+/////////
+
+Take elements from the supplied iterable without consuming it.
+
+.. code-block:: python
+
+    >>> iterable = range(30)
+    >>> first_10 = take(10, iterable)
+    >>> [i for i in first_10]
+    [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
+
+    >>> [i for i in iterable]
+    [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29]
+
+
+.. _`divide`:
+
+**divide**
+////////////
+
+Splits an iterable up into the *specified number of groups*, per `more itertools`_.  Returns an iterable.
+
+.. code-block:: python
+
+    >>> iterable = range(30)
+    >>> groups = []
+    >>> for grp in vistir.misc.divide(3, iterable):
+    ...     groups.append(grp)
+    >>> groups
+    [<tuple_iterator object at 0x7fb7966006a0>, <tuple_iterator object at 0x7fb796652780>, <tuple_iterator object at 0x7fb79650a2b0>]
+
+
+.. _more itertools: https://more-itertools.readthedocs.io/en/latest/api.html#grouping
+
+
 .. _`decode_for_output`:
 
 **decode_for_output**
@@ -411,6 +490,46 @@ outputs using the system preferred locale using ``locale.getpreferredencoding(Fa
 with some additional hackery on linux systems.
 
 
+.. _`get_canonical_encoding_name`:
+
+**get_canonical_encoding_name**
+////////////////////////////////
+
+Given an encoding name, get the canonical name from a codec lookup.
+
+.. code-block:: python
+
+    >>> vistir.misc.get_canonical_encoding_name("utf8")
+    "utf-8"
+
+
+.. _`get_wrapped_stream`:
+
+**get_wrapped_stream**
+//////////////////////
+
+Given a stream, wrap it in a `StreamWrapper` instance and return the wrapped stream.
+
+.. code-block:: python
+
+    >>> stream = sys.stdout
+    >>> wrapped_stream = vistir.misc.get_wrapped_stream(sys.stdout)
+
+
+.. _`StreamWrapper`:
+
+**StreamWrapper**
+//////////////////
+
+A stream wrapper and compatibility class for handling wrapping file-like stream objects
+which may be used in place of ``sys.stdout`` and other streams.
+
+.. code-block:: python
+
+    >>> wrapped_stream = vistir.misc.StreamWrapper(sys.stdout, encoding="utf-8", errors="replace", line_buffering=True)
+    >>> wrapped_stream = vistir.misc.StreamWrapper(io.StringIO(), encoding="utf-8", errors="replace", line_buffering=True)
+
+
 🐉 Path Utilities
 ------------------
 

appveyor.yml

@@ -13,9 +13,9 @@ environment:
 install:
   - "SET PATH=%PYTHON%\\;%PYTHON%\\Scripts;%PATH%"
   - "python --version"
-  - "python -m pip install --upgrade pip pipenv"
+  - "python -m pip install --upgrade pip pipenv pytest pytest-timeout pytest-cov"
   - "python -m pipenv install --dev"
-  - "python -m pipenv run pip install -e .[tests,spinner]"
+  - "python -m pipenv run pip install --upgrade -e .[tests,spinner]"
 
 build: off
 
@@ -24,4 +24,4 @@ test_script:
   - "subst T: %TEMP%"
   - "set TEMP=T:\\"
   - "set TMP=T:\\"
-  - "python -m pipenv run pytest -n auto -v tests"
+  - "python -m pipenv run pytest -ra tests"

docs/conf.py

@@ -12,11 +12,30 @@
 # add these directories to sys.path here. If the directory is relative to the
 # documentation root, use os.path.abspath to make it absolute, like shown here.
 #
+import codecs
 import os
+import re
 import sys
 docs_dir = os.path.abspath(os.path.dirname(__file__))
 src_dir = os.path.join(os.path.dirname(docs_dir), "src", "vistir")
 sys.path.insert(0, src_dir)
+version_file = os.path.join(src_dir, "__init__.py")
+
+
+def read_file(path):
+    # intentionally *not* adding an encoding option to open, See:
+    #   https://github.com/pypa/virtualenv/issues/201#issuecomment-3145690
+    with codecs.open(path, 'r') as fp:
+        return fp.read()
+
+
+def find_version(file_path):
+    version_file = read_file(file_path)
+    version_match = re.search(r"^__version__ = ['\"]([^'\"]*)['\"]",
+                              version_file, re.M)
+    if version_match:
+        return version_match.group(1)
+    return '0.0.0'
 
 
 # -- Project information -----------------------------------------------------
@@ -25,10 +44,12 @@
 copyright = '2018, Dan Ryan <dan@danryan.co>'
 author = 'Dan Ryan <dan@danryan.co>'
 
+release = find_version(version_file)
+version = '.'.join(release.split('.')[:2])
 # The short X.Y version
-version = '0.0'
+# version = '0.0'
 # The full version, including alpha/beta/rc tags
-release = '0.0.0.dev0'
+# release = '0.0.0.dev0'
 
 
 # -- General configuration ---------------------------------------------------
@@ -132,11 +153,11 @@
 latex_elements = {
     # The paper size ('letterpaper' or 'a4paper').
     #
-    # 'papersize': 'letterpaper',
+    'papersize': 'letterpaper',
 
     # The font size ('10pt', '11pt' or '12pt').
     #
-    # 'pointsize': '10pt',
+    'pointsize': '10pt',
 
     # Additional stuff for the LaTeX preamble.
     #
@@ -173,7 +194,7 @@
 #  dir menu entry, description, category)
 texinfo_documents = [
     (master_doc, 'vistir', 'vistir Documentation',
-     author, 'vistir', 'One line description of project.',
+     author, 'vistir', 'Miscellaneous utilities for dealing with filesystems, paths, projects, subprocesses, and more.',
      'Miscellaneous'),
 ]