I have a csv file suitable for an Excel display. The file has column-
names on certain row.
In order to process subsequent rows I want to refer to their columns
symbolically using the column-names. That requires the column-names to
be cleaned up in order to create valid Ruby symbols.
The following worked fine:
if col_name
col_name.gsub!(/[\s]/, "")
col_name.gsub!(/[&]/, "And")
col_name.gsub!(/[#]/, "Number")
end
Each of the following one-liners failed:
col_name.gsub!(/[\s]/, ""). gsub!(/[&]/, "And").gsub!(/[#]/,
"Number") if col_name
col_name.gsub(/[\s]/, ""). gsub(/[&]/, "And").gsub(/[#]/, "Number")
if col_name
I have a csv file suitable for an Excel display. The file has column-
names on certain row.
In order to process subsequent rows I want to refer to their columns
symbolically using the column-names. That requires the column-names to
be cleaned up in order to create valid Ruby symbols.
The following worked fine:
if col_name
col_name.gsub!(/[\s]/, "")
col_name.gsub!(/[&]/, "And")
col_name.gsub!(/[#]/, "Number")
end
Each of the following one-liners failed:
col_name.gsub!(/[\s]/, ""). gsub!(/[&]/, "And").gsub!(/[#]/,
"Number") if col_name
col_name.gsub(/[\s]/, ""). gsub(/[&]/, "And").gsub(/[#]/, "Number")
if col_name
Here is a oneliner
col.gsub!(/[\s&#]/){ |x| x == "#" ? "Number" : x == "&" ? "And" : "" }
just to show that your code is much better.
Why do you dislike it, it is readable and simple.
If you are worried about changes, you might potentially factor that out
[ /\s/, "", "&", "And", "#', "Number"].each_slice( 2 ) do | reg, rep |
col.gsub! reg, rep
end
HTH
Robert
···
On Fri, Apr 10, 2009 at 3:30 AM, RichardOnRails <RichardDummyMailbox58407@uscomputergurus.com> wrote:
.
--
If you want to build a ship, don’t herd people together to collect
wood and don’t assign them tasks and work, but rather teach them to
long for the endless immensity of the sea.
-- Antoine de Saint-Exupery
First off, I still wanted to know what was the flaw in my one-liner;
I found two:
1. I needed carefully placed parenthesis
2. The parenthesized version failed because I just discovered) gsub!
returns nil when no change is made. Bad idea for my purpose; no doubt
Matz saw a good reason for it.
Bob, your version worked fine and fulfills my goal
Ditto for your version, Robert.
For both, I appended "if if col_name" to handle unnamed columns.
With two great choices, my aesthetics lead me to Robert's version
because:
1. I like the x.gsub! ... better than x = x.gsub ...
2. The single gsub! with the choices laid out in order packs expanding
it for additional cases with the least typing.
Again, thank you both very much for your help.
Best wishes,
Richard
Most of all, I like one-liners much better than 5-liners for
readability.
···
On Apr 9, 9:25 pm, RichardOnRails <RichardDummyMailbox58...@USComputerGurus.com> wrote:
Hi,
I have a csv file suitable for an Excel display. The file has column-
names on certain row.
In order to process subsequent rows I want to refer to their columns
symbolically using the column-names. That requires the column-names to
be cleaned up in order to create valid Ruby symbols.
The following worked fine:
if col_name
col_name.gsub!(/[\s]/, "")
col_name.gsub!(/[&]/, "And")
col_name.gsub!(/[#]/, "Number")
end
Each of the following one-liners failed:
col_name.gsub!(/[\s]/, ""). gsub!(/[&]/, "And").gsub!(/[#]/,
"Number") if col_name
col_name.gsub(/[\s]/, ""). gsub(/[&]/, "And").gsub(/[#]/, "Number")
if col_name
Can either of the one-liners be made to work?
The code is show in a larger (easier to read) context athttp://www.pastie.org/442456