toolchain: add binaryornot and prevent yaml import in cookie cutter

tools/external/binaryornot/__init__.py

@@ -0,0 +1,3 @@
+__author__ = 'Audrey Roy'
+__email__ = 'audreyr@gmail.com'
+__version__ = '0.3.0'

tools/external/binaryornot/check.py

@@ -0,0 +1,19 @@
+# -*- coding: utf-8 -*-
+
+"""
+binaryornot.check
+-----------------
+
+Main code for checking if a file is binary or text.
+"""
+
+from .helpers import get_starting_chunk, is_binary_string
+
+
+def is_binary(filename):
+    """
+    :param filename: File to check.
+    :returns: True if it's a binary file, otherwise False.
+    """
+    chunk = get_starting_chunk(filename)
+    return is_binary_string(chunk)

tools/external/binaryornot/helpers.py

@@ -0,0 +1,62 @@
+# -*- coding: utf-8 -*-
+
+"""
+binaryornot.helpers
+-------------------
+
+Helper utilities used by BinaryOrNot.
+"""
+def print_as_hex(s):
+    """
+    Print a string as hex bytes.
+    """
+
+    print(":".join("{0:x}".format(ord(c)) for c in s))
+
+
+def get_starting_chunk(filename, length=1024):
+    """
+    :param filename: File to open and get the first little chunk of.
+    :param length: Number of bytes to read, default 1024.
+    :returns: Starting chunk of bytes.
+    """
+    # Ensure we open the file in binary mode
+    with open(filename, 'rb') as f:
+        chunk = f.read(length)
+        return chunk
+
+
+_printable_extended_ascii = b'\n\r\t\f\b'
+if bytes is str:
+    # Python 2 means we need to invoke chr() explicitly
+    _printable_extended_ascii += b''.join(map(chr, range(32, 256)))
+else:
+    # Python 3 means bytes accepts integer input directly
+    _printable_extended_ascii += bytes(range(32, 256))
+
+def is_binary_string(bytes_to_check):
+    """
+    :param bytes: A chunk of bytes to check.
+    :returns: True if appears to be a binary, otherwise False.
+    """
+    # Uses a simplified version of the Perl detection algorithm,
+    # based roughly on Eli Bendersky's translation to Python:
+    # http://eli.thegreenplace.net/2011/10/19/perls-guess-if-file-is-text-or-binary-implemented-in-python/
+
+    # This is biased slightly more in favour of deeming files as text
+    # files than the Perl algorithm, since all ASCII compatible character
+    # sets are accepted as text, not just utf-8
+
+    # Empty files are considered text files
+    if not bytes_to_check:
+        return False
+
+    # Check for NUL bytes first
+    if b'\x00' in bytes_to_check:
+        return True
+
+    # Now check for a high percentage of ASCII control characters
+    # Binary if control chars are > 30% of the string
+    control_chars = bytes_to_check.translate(None, _printable_extended_ascii)
+    nontext_ratio = float(len(control_chars)) / float(len(bytes_to_check))
+    return nontext_ratio > 0.3

tools/external/cookiecutter/config.py

@@ -14,8 +14,6 @@ import logging
 import os
 import io
 
-import yaml
-
 from .exceptions import ConfigDoesNotExistException
 from .exceptions import InvalidConfiguration
 
@@ -36,6 +34,7 @@ def get_config(config_path):
     if not os.path.exists(config_path):
         raise ConfigDoesNotExistException
 
+    import yaml
     logger.debug('config_path is {0}'.format(config_path))
     with io.open(config_path, encoding='utf-8') as file_handle:
         try: