buildUCD.py: minor refactorings, remove py2-isms

MetaTools/buildUCD.py

@@ -4,24 +4,14 @@ Tools to parse data files from the Unicode Character Database.
 """
 
 
-try:
 from urllib.request import urlopen
-except ImportError:
-    from urllib2 import urlopen
 import re
 import logging
 import os
-from io import open
 from os.path import abspath, dirname, join as pjoin, pardir, sep
 from typing import List
 
 
-try:  # pragma: no cover
-    unicode
-except NameError:
-    unicode = str
-
-
 UNIDATA_URL = "https://unicode.org/Public/UNIDATA/"
 UNIDATA_LICENSE_URL = "http://unicode.org/copyright.html#License"
 
@@ -39,10 +29,18 @@ MAX_UNICODE = 0x10FFFF
 log = logging.getLogger()
 
 
-def open_unidata_file(filename) -> List[str]:
-    """Open a text file from https://unicode.org/Public/UNIDATA/"""
+def read_unidata_file(filename, local_ucd_path=None) -> List[str]:
+    """Read a UCD file from https://unicode.org or optionally from a local directory.
+
+    Return the list of lines.
+    """
+    if local_ucd_path is not None:
+        with open(pjoin(local_ucd_path, filename), "r", encoding="utf-8") as f:
+            return f.readlines()
+    else:
         url = UNIDATA_URL + filename
-    return urlopen(url).read().decode("utf-8").splitlines()
+        with urlopen(url) as response:
+            return response.read().decode("utf-8").splitlines(keepends=True)
 
 
 def parse_unidata_header(file_lines: List[str]):
@@ -55,7 +53,7 @@ def parse_unidata_header(file_lines: List[str]):
             header.append(line)
         else:
             break
-    return "\n".join(header)
+    return "".join(header)
 
 
 def parse_range_properties(infile: List[str], default=None, is_set=False):
@@ -93,9 +91,6 @@ def parse_range_properties(infile: List[str], default=None, is_set=False):
 
     ranges.sort()
 
-    if isinstance(default, unicode):
-        default = str(default)
-
     # fill the gaps between explicitly defined ranges
     last_start, last_end = -1, -1
     full_ranges = []
@@ -178,13 +173,10 @@ def build_ranges(
 
     if local_ucd:
         log.info("loading '%s' from local directory '%s'", filename, local_ucd)
-        file_lines = [
-            l for l in open(pjoin(local_ucd, filename), "r", encoding="utf-8")
-        ]
     else:
         log.info("downloading '%s' from '%s'", filename, UNIDATA_URL)
-        file_lines = open_unidata_file(filename)
 
+    file_lines = read_unidata_file(filename, local_ucd)
     header = parse_unidata_header(file_lines)
     ranges = parse_range_properties(file_lines, default=default, is_set=is_set)
 
@@ -201,7 +193,7 @@ def build_ranges(
         f.write("# Source: {}{}\n".format(UNIDATA_URL, filename))
         f.write("# License: {}\n".format(UNIDATA_LICENSE_URL))
         f.write("#\n")
-        f.write(header + "\n\n")
+        f.write(header + "\n")
 
         f.write("RANGES = [\n")
         for first, last, value in ranges:
@@ -259,12 +251,10 @@ def parse_property_value_aliases(property_tag, local_ucd=None):
     filename = "PropertyValueAliases.txt"
     if local_ucd:
         log.info("loading '%s' from local directory '%s'", filename, local_ucd)
-        file_lines = [
-            l for l in open(pjoin(local_ucd, filename), "r", encoding="utf-8")
-        ]
     else:
         log.info("downloading '%s' from '%s'", filename, UNIDATA_URL)
-        file_lines = open_unidata_file(filename)
+
+    file_lines = read_unidata_file(filename, local_ucd)
     header = parse_unidata_header(file_lines)
     data = parse_semicolon_separated_data(file_lines)