Merge pull request #802 from AnswerDotAI/mapa

Add async mapping utilities: mapa and maybe_aiter

Author: jph00

fastcore/_modidx.py

@@ -818,7 +818,9 @@
                                 'fastcore.xtras.loads_multi': ('xtras.html#loads_multi', 'fastcore/xtras.py'),
                                 'fastcore.xtras.local2utc': ('xtras.html#local2utc', 'fastcore/xtras.py'),
                                 'fastcore.xtras.make_nullable': ('xtras.html#make_nullable', 'fastcore/xtras.py'),
+                                'fastcore.xtras.mapa': ('xtras.html#mapa', 'fastcore/xtras.py'),
                                 'fastcore.xtras.mapped': ('xtras.html#mapped', 'fastcore/xtras.py'),
+                                'fastcore.xtras.maybe_aiter': ('xtras.html#maybe_aiter', 'fastcore/xtras.py'),
                                 'fastcore.xtras.maybe_await': ('xtras.html#maybe_await', 'fastcore/xtras.py'),
                                 'fastcore.xtras.maybe_open': ('xtras.html#maybe_open', 'fastcore/xtras.py'),
                                 'fastcore.xtras.mkdir': ('xtras.html#mkdir', 'fastcore/xtras.py'),

fastcore/xtras.py

@@ -13,12 +13,8 @@
            'stringfmt_names', 'PartialFormatter', 'partial_format', 'truncstr', 'utc2local', 'local2utc', 'trace',
            'modified_env', 'ContextManagers', 'shufflish', 'console_help', 'hl_md', 'type2str', 'dataclass_src',
            'Unset', 'nullable_dc', 'make_nullable', 'flexiclass', 'asdict', 'vars_pub', 'is_typeddict', 'is_namedtuple',
-           'CachedIter', 'CachedAwaitable', 'reawaitable', 'is_async_callable', 'maybe_await', 'noopa', 'flexicache',
-           'time_policy', 'mtime_policy', 'timed_cache']
-
-# %% ../nbs/03_xtras.ipynb #ecd054a6
-#| export
-
+           'CachedIter', 'CachedAwaitable', 'reawaitable', 'is_async_callable', 'maybe_await', 'maybe_aiter', 'mapa',
+           'noopa', 'flexicache', 'time_policy', 'mtime_policy', 'timed_cache']
 
 # %% ../nbs/03_xtras.ipynb #3401d507
 from .imports import *
@@ -1033,6 +1029,21 @@ async def maybe_await(o):
     from inspect import isawaitable
     return await o if isawaitable(o) else o
 
+# %% ../nbs/03_xtras.ipynb #985e3551
+def maybe_aiter(items):
+    "Convert `items` to async generator if needed, and return it"
+    if hasattr(items, '__aiter__'): return items
+    else:
+        async def f(items):
+            for item in items: yield item
+        return f(items)
+
+
+# %% ../nbs/03_xtras.ipynb #371d5196
+async def mapa(f, items):
+    from asyncio import gather
+    return await gather(*[maybe_await(f(o)) async for o in maybe_aiter(items)])
+
 # %% ../nbs/03_xtras.ipynb #02f9f070
 async def noopa(x=None, *args, **kwargs):
     "Do nothing (async)"