Committed patch from Ryan May. It fixes error in loadtxt occurring when usecols is not None and dtypes are given.

I added the test suggested by Ryan.

1 files changed, 6 insertions, 2 deletions

diff --git a/numpy/lib/io.py b/numpy/lib/io.py
index 36723f1d8..b1ae192ec 100644
--- a/numpy/lib/io.py
+++ b/numpy/lib/io.py
@@ -292,8 +292,12 @@ def loadtxt(fname, dtype=float, comments='#', delimiter=None, converters=None,
     if converters is None:
         converters = {}
         if dtype.names is not None:
-            converterseq = [_getconv(dtype.fields[name][0]) \
-                            for name in dtype.names]
+            if usecols is None:
+                converterseq = [_getconv(dtype.fields[name][0]) \
+                                for name in dtype.names]
+            else:
+                converters.update([(col,_getconv(dtype.fields[name][0])) \
+                                    for col,name in zip(usecols, dtype.names)])
 
     for i,line in enumerate(fh):
         if i<skiprows: continue