A different plan for the top-level word_frequency function.

When, before, I was importing wordfreq.query at the top level, this
created a dependency loop when installing wordfreq.

The new top-level __init__.py provides just a `word_frequency` function,
which imports the real function as needed and calls it. This should
avoid the dependency loop, at the cost of making
`wordfreq.word_frequency` slightly less efficient than
`wordfreq.query.word_frequency`.

tests/test_queries.py

@@ -1,6 +1,7 @@
 from __future__ import unicode_literals
 from nose.tools import eq_, assert_almost_equal, assert_greater
-from wordfreq.query import (word_frequency, average_frequency, wordlist_size,
+from wordfreq import word_frequency
+from wordfreq.query import (average_frequency, wordlist_size,
                             wordlist_info)
 
 

wordfreq/__init__.py

@@ -1,2 +1,16 @@
-# Import some methods from wordfreq.query at the top level.
+# Make wordfreq.query available at the top level when needed.
-from wordfreq.query import word_frequency, iter_wordlist, random_words
+
+def word_frequency(word, lang, wordlist='multi', offset=0.):
+    """
+    Get the frequency of `word` in the language with code `lang`, from the
+    specified `wordlist`.
+
+    The offset gets added to all values, to monotonically account for the
+    fact that we have not observed all possible words.
+
+    This is a wrapper for the real word_frequency function, so that it can
+    be imported at the top level instead of from `wordfreq.query`.
+    """
+    from wordfreq.query import word_frequency as _real_word_frequency
+    return _real_word_frequency(word, lang, wordlist=wordlist, offset=offset)
+