Moved misc functions from polyglot package to single polyglot module.

ebook_converter/polyglot.py

@@ -0,0 +1,59 @@
+"""
+Misc converting functions from polyglot module.
+Most of the have something to do with converting between string and binary
+"""
+import base64
+import binascii
+import urllib
+
+
+def as_base64_unicode(x, enc='utf-8'):
+    if isinstance(x, str):
+        x = x.encode(enc)
+    return base64.standard_b64encode(x).decode('ascii')
+
+
+def from_base64_bytes(x):
+    if isinstance(x, str):
+        x = x.encode('ascii')
+    return base64.standard_b64decode(x)
+
+
+def as_hex_bytes(x, enc='utf-8'):
+    if isinstance(x, str):
+        x = x.encode(enc)
+    return binascii.hexlify(x)
+
+
+def from_hex_bytes(x):
+    if isinstance(x, str):
+        x = x.encode('ascii')
+    return binascii.unhexlify(x)
+
+
+def as_bytes(x, encoding='utf-8'):
+    if isinstance(x, str):
+        return x.encode(encoding)
+    if isinstance(x, bytes):
+        return x
+    if isinstance(x, bytearray):
+        return bytes(x)
+    if isinstance(x, memoryview):
+        return x.tobytes()
+    return str(x).encode(encoding)
+
+
+def unquote(x, encoding='utf-8', errors='replace'):
+    # TODO(gryf): this works like that: if x is a binary, convert it to
+    # string using encoding and make unquote. After that make it binary again.
+    # If x is string, just pass it to the unquote.
+    # This approach is mostly used within lxml etree strings, which suppose to
+    # be binary because of its inner representation. I'm wondering, if
+    # xml.etree could be used instead - to be checked.
+    binary = isinstance(x, bytes)
+    if binary:
+        x = x.decode(encoding, errors)
+    ans = urllib.parse.unquote(x, encoding, errors)
+    if binary:
+        ans = ans.encode(encoding, errors)
+    return ans