[describe-] collect aggr funcs that operate on list of values in Orde…

…redDict

aggregator() converts a func, which operates on a list, into a _func,
which operates on a srccol and a list of rows.

The original functions were then added into Globals, but this caused problems for
a function like `sum()` which appears naturally in Python code.

I created an OrderedDict, and named it aggregators_vals as a place to
store them.

Other possible options:

* We could include the optional funcvals along with func(srccol) for
Aggregator. Describe Sheet could then grab the funcvals if it exists.

* Describe Sheet could pass the srccol and list of rows, instead of
vals. This is not ideal because it means for each aggregator, we call
getValues once-more. This would cause a performance degradation.

* Add them to vd.aggregators, possibly with the suffix "_vals", and
create an Aggregator out of them as well. Have Describe Sheet pull
aggrname_vals.

* Similarly use the vd.aggregator_vals, but have a less terrible name.

Optional: Do we want to do the work of porting quantiles and percentiles to be useable by Describe Sheet? Currently, an aggregator that does not go through aggregator() is not useable by Describe Sheet.

visidata/aggregators.py

@@ -30,7 +30,8 @@ def getValues(self, rows):
         yield v
 
 
-vd.aggregators = collections.OrderedDict()  # [aggname] -> annotated func, or list of same
+vd.aggregators = collections.OrderedDict()  # [aggname] -> annotated func, or list of same - srccol and list of rows parameters
+vd.aggregators_vals = collections.OrderedDict()  # [aggname] -> annotated func - list of values parameters
 
 Column.init('aggstr', str, copy=True)
 
@@ -80,8 +81,8 @@ def _func(col, rows):  # wrap builtins so they can have a .type
                 return None
             return e
 
-    vd.aggregators[name] = _defaggr(name, type, _func, helpstr)
-    vd.addGlobals({name: func})
+    vd.aggregators[name] = _defaggr(name, type, _func, helpstr)  # accepts a srccol + list of rows
+    vd.aggregators_vals[name] = func
 
 ## specific aggregator implementations
 

visidata/features/describe.py

@@ -94,17 +94,16 @@ def reloadColumn(self, srccol):
                 except Exception as e:
                     d['errors'].append(sr)
 
-            d['mode'] = self.calcStatistic(d, mode, vals)
+            d['mode'] = self.calcStatistic(mode, vals)
             if vd.isNumeric(srccol):
                 for func in [min, max, sum, median]:  # use type
-                    d[func.__name__] = self.calcStatistic(d, func, vals)
+                    d[func.__name__] = self.calcStatistic(func, vals)
                 for aggrname in vd.options.describe_aggrs.split():
-                    func = vd.getGlobals()[aggrname]
-                    d[func.__name__] = self.calcStatistic(d, func, vals)
+                    aggr = vd.aggregators_vals[aggrname]
+                    d[aggrname] = self.calcStatistic(aggr, vals)
 
-    def calcStatistic(self, d, func, *args, **kwargs):
+    def calcStatistic(self, func, *args, **kwargs):
         r = wrapply(func, *args, **kwargs)
-        d[func.__name__] = r
         return r
 
     def openCell(self, col, row):