Enforce pep8 coding style

.travis.yml

@@ -7,6 +7,6 @@ python:
   - "3.7"
   - "3.8"
 install:
-  - pip install tox-travis
+  - pip install tox-travis flake8
 script:
   - tox -r

CHANGELOG.md

@@ -5,6 +5,9 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 ## [Unreleased]
 
+### Changed
+- Enforce pep8 coding style by adding flake8 to CI ([#345](https://github.com/pdfminer/pdfminer.six/pull/345))
+
 ## [20191110] - 2019-11-10
 
 ### Fixed

CONTRIBUTING.md

@@ -14,7 +14,7 @@ Any contribution is appreciated! You might want to:
     - If you report a bug in the results for a particular pdf, include that pdf. This allows others to replicate the
      issue. 
 * Fix issues by [creating pull requests](https://help.github.com/en/articles/creating-a-pull-request).
-* Help others by giving your thoughts on open issues and pull requests.
+* Help others by sharing your thoughs in comments on issues and pull requests.
 
 ## Guidelines for creating issues
 
@@ -29,11 +29,15 @@ Any contribution is appreciated! You might want to:
 * Pull requests should be merged to develop, not master. This ensures that master always equals the released version.  
 * Include unit tests when possible. In case of bugs, this will help to prevent the same mistake in the future. In case 
   of features, this will show that your code works correctly.
-* Code should work for Python 2.7 and Python 3.x (for now), conform to PEP8 code style (with a line-width of 120) 
-  and properly documented with docstrings.
+* Code should work for Python 2.7 and Python 3.x (for now), conform to PEP8 code style (enforced by 
+  [flake8](http://flake8.pycqa.org/en/latest/)) and properly documented with docstrings.
 * Check spelling and grammar.
 * Don't forget to update the [CHANGELOG.md](CHANGELOG.md#[Unreleased])
 
+## Guidelines for posting comments
+
+* [Be cordial and positive](https://www.kennethreitz.org/essays/be-cordial-or-be-on-your-way)
+
 ## Getting started
 
 1. Clone the repository

docs/source/conf.py

@@ -12,7 +12,8 @@
 
 import os
 import sys
-sys.path.insert(0, os.path.join(os.path.abspath(os.path.dirname(__file__)), '../../'))
+sys.path.insert(0, os.path.join(
+    os.path.abspath(os.path.dirname(__file__)), '../../'))
 
 
 # -- Project information -----------------------------------------------------
@@ -58,4 +59,4 @@
 # Add any paths that contain custom static files (such as style sheets) here,
 # relative to this directory. They are copied after the builtin static files,
 # so a file named "default.css" will overwrite the builtin "default.css".
-html_static_path = ['_static']
+html_static_path = ['_static']

pdfminer/__init__.py

@@ -17,8 +17,11 @@
 
 
 if sys.version_info < (3, 0):
-    warnings.warn('On January 1st, 2020, pdfminer.six will stop supporting Python 2. Please upgrade to Python 3. For '
-                  'more information see https://github.com/pdfminer/pdfminer.six/issues/194')
+    warnings.warn('On January 1st, 2020, '
+                  'pdfminer.six will stop supporting Python 2. '
+                  'Please upgrade to Python 3. '
+                  'For more information see '
+                  'https://github.com/pdfminer/pdfminer.six/issues/194')
 
 if __name__ == '__main__':
     print(__version__)

pdfminer/arcfour.py

@@ -6,17 +6,18 @@
 
 """
 
-import six # Python 2+3 compatibility
-##  Arcfour
-##
+import six  # Python 2+3 compatibility
+
+
 class Arcfour(object):
 
     def __init__(self, key):
-        s = [i for i in range(256)] #because Py3 range is not indexable
+        # because Py3 range is not indexable
+        s = [i for i in range(256)]
         j = 0
         klen = len(key)
         for i in range(256):
-            j = (j + s[i] + six.indexbytes(key,i % klen)) % 256
+            j = (j + s[i] + six.indexbytes(key, i % klen)) % 256
             (s[i], s[j]) = (s[j], s[i])
         self.s = s
         (self.i, self.j) = (0, 0)
@@ -34,7 +35,8 @@ def process(self, data):
             r += six.int2byte(c ^ k)
         (self.i, self.j) = (i, j)
         return r
-    
+
     encrypt = decrypt = process
 
+
 new = Arcfour

pdfminer/ascii85.py

@@ -9,7 +9,7 @@
 import re
 import struct
 
-import six #Python 2+3 compatibility
+import six  # Python 2+3 compatibility
 
 
 # ascii85decode(data)
@@ -27,7 +27,7 @@ def ascii85decode(data):
     n = b = 0
     out = b''
     for i in six.iterbytes(data):
-        c=six.int2byte(i)
+        c = six.int2byte(i)
         if b'!' <= c and c <= b'u':
             n += 1
             b = b*85+(ord(c)-33)
@@ -45,9 +45,11 @@ def ascii85decode(data):
             break
     return out
 
+
 # asciihexdecode(data)
-hex_re = re.compile(b'([a-f\d]{2})', re.IGNORECASE)
-trail_re = re.compile(b'^(?:[a-f\d]{2}|\s)*([a-f\d])[\s>]*$', re.IGNORECASE)
+hex_re = re.compile(b'([a-f0-9]{2})', re.IGNORECASE)
+trail_re = re.compile(b'^(?:[a-f0-9]{2}|[ \t\n\r\f\v])*'
+                      b'([a-f0-9])[ \t\n\r\f\v>]*$', re.IGNORECASE)
 
 
 def asciihexdecode(data):
@@ -61,14 +63,14 @@ def asciihexdecode(data):
     will behave as if a 0 followed the last digit.
     """
     def decode(x):
-        i=int(x,16)
+        i = int(x, 16)
         return six.int2byte(i)
 
-    out=b''
+    out = b''
     for x in hex_re.findall(data):
-        out+=decode(x)
+        out += decode(x)
 
     m = trail_re.search(data)
     if m:
-        out+=decode(m.group(1)+b'0')
+        out += decode(m.group(1)+b'0')
     return out