Comments (2)
CSV
object behaves like an IO
. IO
consumes data by reading. You can't read data again without seeking.
require "stringio"
lines = StringIO.new("a\nb\nc\n").each_line
p lines.first # => "a\n"
p lines.first # => "b\n"
p lines.first # => "c\n"
If you don't want to consume data with Enumerable
methods such as #count
and #first
, you can use CSV#to_a
or CSV#rewind
:
require 'csv'
raw =<<~EOF
name,age
tom,13
bob,14
alice,15
EOF
csv = CSV.new(raw, headers: true)
rows = csv.to_a
puts rows.count #=> 3
puts rows.count #=> 3
csv = CSV.new(raw, headers: true)
rows = csv.to_a
puts rows.first['name'] #=> tom
puts rows.first['name'] #=> tom
puts rows.first['name'] #=> tom
csv = CSV.new(raw, headers: true)
puts csv.count #=> 3
csv.rewind
puts csv.count #=> 3
csv = CSV.new(raw, headers: true)
puts csv.first['name'] #=> tom
csv.rewind
puts csv.first['name'] #=> tom
csv.rewind
puts csv.first['name'] #=> tom
from csv.
I got it. Using to_a
way seems better for my case.
Thank you @kou !
from csv.
Related Issues (20)
- New bugfix version for the changes on master HOT 1
- CSV.generate is not working with Rails 7 HOT 18
- `CSV::Row` pattern matching `Symbol` assumption HOT 1
- :date_time converter fails to recognize "YYYY-MM-DD HH:MM" HOT 7
- Add quoted information to CSV::FieldInfo HOT 1
- ArgumentError: unknown encoding name - iso-8859-1|utf-8 HOT 2
- Feature Request: Generate CSV String from Array HOT 5
- #eof? method returning wrong value when it's used on a csv file HOT 3
- #eof? method returning wrong value when it's used on a csv file with #each, #map, #filter HOT 1
- New release for Ruby 3.2 HOT 7
- How about GH releases generated by `gh release create --generate-notes` HOT 5
- feature: add option to limit length of strings HOT 3
- Suggestion to add `sep` option HOT 1
- Broken links in documention HOT 11
- Duplicated last line in CSV.foreach HOT 14
- Recipes not copied downstream HOT 6
- A fiber to execute ':heder_converters' has been changed since v3.2.6 HOT 1
- liberal parsing does not split column as expected with quote at end of column HOT 8
- Inconsistent behaviour between `CSV::Table.new` and `CSV.parse` HOT 10
Recommend Projects
-
React
A declarative, efficient, and flexible JavaScript library for building user interfaces.
-
Vue.js
🖖 Vue.js is a progressive, incrementally-adoptable JavaScript framework for building UI on the web.
-
Typescript
TypeScript is a superset of JavaScript that compiles to clean JavaScript output.
-
TensorFlow
An Open Source Machine Learning Framework for Everyone
-
Django
The Web framework for perfectionists with deadlines.
-
Laravel
A PHP framework for web artisans
-
D3
Bring data to life with SVG, Canvas and HTML. 📊📈🎉
-
Recommend Topics
-
javascript
JavaScript (JS) is a lightweight interpreted programming language with first-class functions.
-
web
Some thing interesting about web. New door for the world.
-
server
A server is a program made to process requests and deliver data to clients.
-
Machine learning
Machine learning is a way of modeling and interpreting data that allows a piece of software to respond intelligently.
-
Visualization
Some thing interesting about visualization, use data art
-
Game
Some thing interesting about game, make everyone happy.
Recommend Org
-
Facebook
We are working to build community through open source technology. NB: members must have two-factor auth.
-
Microsoft
Open source projects and samples from Microsoft.
-
Google
Google ❤️ Open Source for everyone.
-
Alibaba
Alibaba Open Source for everyone
-
D3
Data-Driven Documents codes.
-
Tencent
China tencent open source team.
from csv.