Get rid of subprocess call on import of tesseract, unpaper -- bit nasty

2015-07-28 01:00:29 -07:00
parent 8508141314
commit 6064160953
3 changed files with 23 additions and 31 deletions
@@ -54,11 +54,11 @@ EXIT_OTHER_ERROR = 15

 MINIMUM_TESS_VERSION = '3.02.02'

-if tesseract.VERSION < MINIMUM_TESS_VERSION:
+if tesseract.version() < MINIMUM_TESS_VERSION:
    print(
        "Please install tesseract {0} or newer "
        "(currently installed version is {1})".format(
-            MINIMUM_TESS_VERSION, tesseract.VERSION),
+            MINIMUM_TESS_VERSION, tesseract.version()),
        file=sys.stderr)
    sys.exit(EXIT_MISSING_DEPENDENCY)

@@ -177,12 +177,12 @@ if not options.language:
 if '+' in options.language[0]:
    options.language = options.language[0].split('+')

-if not set(options.language).issubset(tesseract.LANGUAGES):
+if not set(options.language).issubset(tesseract.languages()):
    print(
        "The installed version of tesseract does not have language "
        "data for the following requested languages: ",
        file=sys.stderr)
-    for lang in (set(options.language) - tesseract.LANGUAGES):
+    for lang in (set(options.language) - tesseract.languages()):
        print(lang, file=sys.stderr)
    sys.exit(EXIT_BAD_ARGS)

@@ -1,43 +1,41 @@
 #!/usr/bin/env python3

-from subprocess import Popen, PIPE, CalledProcessError
+from subprocess import STDOUT, CalledProcessError, check_output
 import sys
 import os
 import re
+from functools import lru_cache


-def _version():
+@lru_cache(maxsize=1)
+def version():
    args_tess = [
        'tesseract',
        '--version'
    ]
-    p_tess = Popen(args_tess, close_fds=True, universal_newlines=True,
-                   stdout=PIPE, stderr=PIPE)
-    _, versions = p_tess.communicate(timeout=5)
+    try:
+        versions = check_output(
+                args_tess, close_fds=True, universal_newlines=True,
+                stderr=STDOUT)
+    except CalledProcessError:
+        print("Could not find Tesseract executable on system PATH.")
+        sys.exit(1)

    tesseract_version = re.match(r'tesseract\s(.+)', versions).group(1)
    return tesseract_version


-def _languages():
+@lru_cache(maxsize=1)
+def languages():
    args_tess = [
        'tesseract',
        '--list-langs'
    ]
-    p_tess = Popen(args_tess, close_fds=True, universal_newlines=True,
-                   stdout=PIPE, stderr=PIPE)
-    _, langs = p_tess.communicate(timeout=5)
-
+    langs = check_output(
+            args_tess, close_fds=True, universal_newlines=True,
+            stderr=STDOUT)
    return set(lang.strip() for lang in langs.splitlines()[1:])

-try:
-    VERSION = _version()
-    LANGUAGES = _languages()
-except Exception as e:
-    print(e)
-    print("Could not find tesseract executable", file=sys.stderr)
-
-    sys.exit(1)

 HOCR_TEMPLATE = '''<?xml version="1.0" encoding="UTF-8"?>
 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
@@ -6,9 +6,11 @@ from subprocess import Popen, PIPE
 from tempfile import NamedTemporaryFile
 import sys
 import os
+from functools import lru_cache


-def _version():
+@lru_cache(maxsize=1)
+def version():
    args_unpaper = [
        'unpaper',
        '--version'
@@ -20,14 +22,6 @@ def _version():
    return version.strip()


-try:
-    VERSION = _version()
-    AVAILABLE = True
-except FileNotFoundError:
-    VERSION = '?'
-    AVAILABLE = False
-    raise
-
 try:
    from PIL import Image
 except ImportError: