Add Python 3.7 support

.travis.yml

@@ -36,11 +36,15 @@ matrix:
     - os: linux
       sudo: required
       language: python
-      python: 3.5
+      python: "3.5"
     - os: linux
       sudo: required
       language: python
-      python: 3.6
+      python: "3.6"
+    - os: linux
+      sudo: required
+      language: python
+      python: "3.7-dev"
     - os: osx
       osx_image: xcode8
       language: generic

README.rst

@@ -4,10 +4,10 @@ OCRmyPDF
 .. image:: https://travis-ci.org/jbarlow83/OCRmyPDF.svg?branch=master
     :target: https://travis-ci.org/jbarlow83/OCRmyPDF
 
-.. image:: https://img.shields.io/pypi/v/ocrmypdf.svg   
+.. image:: https://img.shields.io/pypi/v/ocrmypdf.svg
     :target: https://pypi.org/project/ocrmypdf/
 
-.. image:: https://img.shields.io/homebrew/v/ocrmypdf.svg   
+.. image:: https://img.shields.io/homebrew/v/ocrmypdf.svg
     :alt: homebrew
     :target: http://brewformulas.org/Ocrmypdf
 
@@ -53,7 +53,7 @@ Motivation
 I searched the web for a free command line tool to OCR PDF files on
 Linux/UNIX: I found many, but none of them were really satisfying.
 
--  Either they produced PDF files with misplaced text under the image (making copy/paste impossible) 
+-  Either they produced PDF files with misplaced text under the image (making copy/paste impossible)
 -  Or they did not handle accents and multilingual characters
 -  Or they changed the resolution of the embedded images
 -  Or they generated ridiculously large PDF files
@@ -62,7 +62,7 @@ Linux/UNIX: I found many, but none of them were really satisfying.
 -  On top of that none of them produced PDF/A files (format dedicated for long time storage)
 
 ...so I decided to develop my own tool (using various existing scripts
-as an inspiration). 
+as an inspiration).
 
 Installation
 ------------
@@ -96,7 +96,7 @@ you can often find packages that provide language packs:
 
    # Debian/Ubuntu users
    apt-get install tesseract-ocr-chi-sim  # Example: Install Chinese Simplified language back
-   
+
 You can then pass the ``-l LANG`` argument to OCRmyPDF to give a hint as to what languages it should search for. Multiple
 languages can be requested.
 
@@ -125,9 +125,7 @@ If you detect an issue, please:
 Requirements
 ------------
 
-Runs on CPython 3.6, and requires external program installations of Ghostscript, Tesseract OCR, QPDF, and Leptonica. ocrmypdf is pure Python, but uses CFFI to portably generate library bindings.
+Runs on CPython 3.5, 3.6 and 3.7. Requires external program installations of Ghostscript, Tesseract OCR, QPDF, and Leptonica. ocrmypdf is pure Python, but uses CFFI to portably generate library bindings.
-
-Python 3.5 is also supported.
 
 Press & Media
 -------------
@@ -141,7 +139,7 @@ Press & Media
 License
 -------
 
-The OCRmyPDF software is licensed under the GNU GPLv3. Certain files are covered by other licenses, as noted in their source files. 
+The OCRmyPDF software is licensed under the GNU GPLv3. Certain files are covered by other licenses, as noted in their source files.
 
 The license for each test file varies, and is noted in tests/resources/README.rst. The documentation is licensed under Creative Commons Attribution-ShareAlike 4.0 (CC-BY-SA 4.0).
 

docs/installation.rst

@@ -168,7 +168,7 @@ Install or upgrade the required Homebrew packages, if any are missing:
     brew install libxml2 libffi leptonica
     brew install unpaper   # optional
 
-Python 3.5 and 3.6 are supported.
+Python 3.5, 3.6 and 3.7 are supported.
 
 Install the required Tesseract OCR engine with the language packs you plan to use:
 

setup.py

@@ -221,6 +221,7 @@ setup(
     classifiers=[
         "Programming Language :: Python :: 3.5",
         "Programming Language :: Python :: 3.6",
+        "Programming Language :: Python :: 3.7",
         "Development Status :: 5 - Production/Stable",
         "Environment :: Console",
         "Intended Audience :: End Users/Desktop",

src/ocrmypdf/_unicodefun.py

@@ -40,6 +40,11 @@ import codecs
 
 def verify_python3_env():
     """Ensures that the environment is good for unicode on Python 3."""
+
+    # PEP 538 changes in Python 3.7 should make this wrangling unnecessary
+    if sys.version_info[0:3] >= (3, 7, 0):
+        return
+
     try:
         import locale
         fs_enc = codecs.lookup(locale.getpreferredencoding()).name