go_iterscraper

README

Note: this is taken from https://github.com/philipithomas an being used here as a refactor exercise.

iterscraper

A basic package used for scraping information from a website where URLs contain an incrementing integer. Information is retrieved from HTML5 elements, and outputted as a CSV.

Flags

Flags are all optional, and are set with a single dash on the command line, e.g.

iterscraper \
-url            "http://foo.com/%d" \
-from           1                   \
-to             10                  \
-concurrency    10                  \
-output         foo.csv             \
-nameQuery      ".name"             \
-addressQuery   ".address"          \
-phoneQuery     ".phone"            \
-emailQuery     ".email"            

For an explanation of the options, type iterscraper -help

General usage of iterscraper:

  -addressQuery string
        JQuery-style query for the address element (default ".address")
  -concurrency int
        How many scrapers to run in parallel. (More scrapers are faster, but more prone to rate limiting or bandwith issues) (default 1)
  -emailQuery string
        JQuery-style query for the email element (default ".email")
  -from int
        The first ID that should be searched in the URL - inclusive.
  -nameQuery string
        JQuery-style query for the name element (default ".name")
  -output string
        Filename to export the CSV results (default "output.csv")
  -phoneQuery string
        JQuery-style query for the phone element (default ".phone")
  -to int
        The last ID that should be searched in the URL - exclusive (default 1)
  -url string
        The URL you wish to scrape, containing "%d" where the id should be substituted (default "http://example.com/v/%d")

URL Structure

Successive pages must look like:

http://example.com/foo/1/bar
http://example.com/foo/2/bar
http://example.com/foo/3/bar

iterscraper would then accept the url in the following style, in Printf style such that numbers may be substituted into the url:

http://example.com/foo/%d/bar

Installation

Building the source requires the Go programming language and the Glide package manager.

# Dependency is GoQuery
go get github.com/PuerkitoBio/goquery
# Get and build source
go get github.com/philipithomas/iterscraper
# If your $PATH is configured correctly, you can call it directly
iterscraper [flags]

Errata

• This is purpose-built for some internal scraping. It's not meant to be the scraping tool for every user case, but you're welcome to modify it for your purposes
• On a 429 - too many requests error, the app stops. This is because data integrity (being able to tell whether or not a page exists) is compromised. One possible fix is to turn down concurrency.
• The package will follow up to 10 redirects
• On a 404 - not found error, the system will log the miss, then continue. It is not exported to the CSV.