Yichao,
I'm afraid I'm not following -- could you expand on that a bit? Thanks,
Alex
On Wednesday, October 19, 2016 at 4:41:30 PM UTC-7, Yichao Yu wrote:
>
> On Oct 19, 2016 7:26 PM, "Alex Mellnik" <a.r.m...@gmail.com <javascript:>>
> wrote:
> >
> > Here's my bizarre find of the day. Most functions can be overwritten
> without problems:
> >
> > function add7(i)
> > 7 + i
> > end
> > Out[1]:
> > add7 (generic function with 1 method)
> > In [2]:
> >
> > add7(0)
> > add7(0)
> > Out[2]:
> > 7
> > In [3]:
> >
> > function add7(i)
> > 9 + i
> > end
> > function add7(i)
> > 9 + i
> > end
> > Out[3]:
> > add7 (generic function with 1 method)
> > WARNING: Method definition add7(Any) in module Main at In[1]:2
> overwritten at In[3]:2.
> > In [4]:
> >
> > add7(0)
> > Out[4]:
> > 9
> >
> > However, others can not:
> >
> > using DataFrames
> > df = DataFrame(A=[1,2,3], B=["A", "B", "C"])
> > println(df)
> > 3×2 DataFrames.DataFrame
> > │ Row │ A │ B │
> > ├─────┼───┼─────┤
> > │ 1 │ 1 │ "A" │
> > │ 2 │ 2 │ "B" │
> > │ 3 │ 3 │ "C" │
> > In [3]:
> >
> > row[:A] > 2
> > function filter(row)
> > if row[:A] > 2
> > return 1
> > else
> > return 3
> > end
> > end
> > Out[3]:
> > filter (generic function with 1 method)
> > In [4]:
> >
> > [filter(row) for row in eachrow(df)]
> > [filter(row) for row in eachrow(df)]
> > Out[4]:
> > 3-element Array{Int64,1}:
> > 3
> > 3
> > 1
> > In [5]:
> >
> > rand() > 0.5
> > function filter(row)
> > if row[:A] > 2
> > return 2
> > else
> > return 4
> > end
> > end
> > WARNING: Method definition filter(Any) in module Main at In[3]:2
> overwritten at In[5]:2
> > Out[5]:
> > filter (generic function with 1 method)
> > .
> > In [6]:
> >
> > [filter(row) for row in eachrow(df)]
> > Out[6]:
> > 3-element Array{Int64,1}:
> > 3
> > 3
> > 1
> >
> > What is it about this second example that prevents the newer method from
> being used?
>
> Nothing about it but how you use it. It's inlined to the comprehension.
>
>
