Thank you very much Milan !
When I searched a solution in DataFrame documentation I did not found the
keyword "similar". Is there an equivalent for Julia of this website
<http://perldoc.perl.org/index-functions-by-cat.html>for Perl for example ?
julia> df = readtable("test2.tsv")
4x4 DataFrames.DataFrame
│ Row │ row1 │ x3_39 │ x2_5 │ x4_5 │
┝━━━━━┿━━━━━━━━┿━━━━━━━┿━━━━━━┿━━━━━━┥
│ 1 │ "row2" │ 3.46 │ 2.7 │ 4.8 │
│ 2 │ "row3" │ 3.58 │ 2.9 │ 4.7 │
│ 3 │ "row4" │ 3.7 │ 2.7 │ 4.9 │
│ 4 │ "row5" │ 3.81 │ 3.0 │ 5.3 │
julia> m = similar(df,0)
0x4 DataFrames.DataFrame
julia> m
0x4 DataFrames.DataFrame
julia> df[2,:]
1x4 DataFrames.DataFrame
│ Row │ row1 │ x3_39 │ x2_5 │ x4_5 │
┝━━━━━┿━━━━━━━━┿━━━━━━━┿━━━━━━┿━━━━━━┥
│ 1 │ "row3" │ 3.58 │ 2.9 │ 4.7 │
julia> append!(m, df[2,:])
1x4 DataFrames.DataFrame
│ Row │ row1 │ x3_39 │ x2_5 │ x4_5 │
┝━━━━━┿━━━━━━━━┿━━━━━━━┿━━━━━━┿━━━━━━┥
│ 1 │ "row3" │ 3.58 │ 2.9 │ 4.7 │
julia> m
1x4 DataFrames.DataFrame
│ Row │ row1 │ x3_39 │ x2_5 │ x4_5 │
┝━━━━━┿━━━━━━━━┿━━━━━━━┿━━━━━━┿━━━━━━┥
│ 1 │ "row3" │ 3.58 │ 2.9 │ 4.7 │
