Fix findnocoding.p and pysource.py scripts

I suppose that these scripts didn't work since Python 3.0.

Tools/scripts/findnocoding.py

@@ -32,7 +32,7 @@ except ImportError:
                          "no sophisticated Python source file search will be done.", file=sys.stderr)
 
 
-decl_re = re.compile(r"coding[=:]\s*([-\w.]+)")
+decl_re = re.compile(rb"coding[=:]\s*([-\w.]+)")
 
 def get_declaration(line):
     match = decl_re.search(line)
@@ -50,10 +50,11 @@ def has_correct_encoding(text, codec):
 
 def needs_declaration(fullpath):
     try:
-        infile = open(fullpath)
+        infile = open(fullpath, 'rb')
     except IOError: # Oops, the file was removed - ignore it
         return None
 
+    with infile:
         line1 = infile.readline()
         line2 = infile.readline()
 
@@ -64,7 +65,6 @@ def needs_declaration(fullpath):
 
         # check the whole file for non utf-8 characters
         rest = infile.read()
-    infile.close()
 
     if has_correct_encoding(line1+line2+rest, "utf-8"):
         return False

Tools/scripts/pysource.py

@@ -22,7 +22,7 @@ __all__ = ["has_python_ext", "looks_like_python", "can_be_compiled", "walk_pytho
 
 import os, re
 
-binary_re = re.compile('[\x00-\x08\x0E-\x1F\x7F]')
+binary_re = re.compile(br'[\x00-\x08\x0E-\x1F\x7F]')
 
 debug = False
 
@@ -42,7 +42,7 @@ def _open(fullpath):
         return None
 
     try:
-        return open(fullpath)
+        return open(fullpath, "rb")
     except IOError as err: # Access denied, or a special file - ignore it
         print_debug("%s: access denied: %s" % (fullpath, err))
         return None
@@ -65,7 +65,7 @@ def looks_like_python(fullpath):
 
     if fullpath.endswith(".py") or fullpath.endswith(".pyw"):
         return True
-    elif "python" in line:
+    elif b"python" in line:
         # disguised Python script (e.g. CGI)
         return True