For your assignment you may be using different dataset than what is included here.
Always read carefully the instructions on Sakai.
Tasks/questions to be completed/answered are highlighted in larger bolded fonts and numbered according to their section.
Web scraping, web harvesting, or web data extraction is data scraping used for extracting data from websites.
This technique mostly focuses on the transformation of unstructured data (HTML format) on the web into structured data (database or spreadsheet)
A fictitious London-based training company, WeTrainYou, wants to start a local training facility in California. It is looking for a city where ample Salesforce* development jobs are available.
Its goal is to train engineers and fulfill full-time and part-time jobs. WeTrainYou has hired you to determine where they should set up the business.
Case Study: https://software.intel.com/en-us/articles/using-visualization-to-tell-a-compelling-data-story
We are going to use tidyverse a collection of R packages designed for data science.
## Loading required package: tidyverse
## ── Attaching packages ──────────────────────────────────────────────────────────────────────── tidyverse 1.2.1 ──
## ✔ ggplot2 2.2.1 ✔ purrr 0.2.4
## ✔ tibble 1.4.2 ✔ dplyr 0.7.4
## ✔ tidyr 0.7.2 ✔ stringr 1.2.0
## ✔ readr 1.1.1 ✔ forcats 0.2.0
## ── Conflicts ─────────────────────────────────────────────────────────────────────────── tidyverse_conflicts() ──
## ✖ dplyr::filter() masks stats::filter()
## ✖ dplyr::lag() masks stats::lag()
## Loading required package: rvest
## Loading required package: xml2
##
## Attaching package: 'rvest'
## The following object is masked from 'package:purrr':
##
## pluck
## The following object is masked from 'package:readr':
##
## guess_encoding
# This function to creates a URL for the www.dice.com website and extract the data
create_url <- function(website, title, location, radius, page){
url <- paste0(website, "?q=", title, "&l=", location, "&radius=", radius)
url <- paste0(url, "&startPage=", page, "&jobs")
return(url)
}
# This function use the unstructure data from the html file to create a dataframe
# with only the data that is needed for analysis
create_tibble <- function(html){
search_title <- html %>%
html_nodes(".complete-serp-result-div") %>%
html_nodes(xpath = "//a/@title") %>%
html_text()
search_region <- html %>%
html_nodes(".complete-serp-result-div") %>%
html_nodes('[itemprop="address"]') %>%
html_nodes("[itemprop=addressRegion]") %>%
html_text()
search_zipcode <- html %>%
html_nodes(".complete-serp-result-div") %>%
html_nodes('[itemprop="address"]') %>%
html_nodes("[itemprop=postalCode]") %>%
html_text()
search_address <- html %>%
html_nodes(".complete-serp-result-div") %>%
html_nodes('[itemprop="address"]') %>%
html_nodes("[itemprop=streetAddress]") %>%
html_text() %>%
str_replace(pattern = paste0(", ",search_region), "")
search_company <- html %>%
html_nodes(".complete-serp-result-div") %>%
html_nodes('[itemprop="hiringOrganization"]') %>%
html_nodes("[itemprop=name]") %>%
html_text()
df <- tibble(title = search_title,
company = search_company,
city = search_address,
state = search_region,
zipcode = search_zipcode)
return(df)
}
#Paste the link that is provided into safari and take a screenshot of the data that you need.
site = "https://www.dice.com/jobs"
job = "Data+Analyst"
region = "NY"
miles = 30
pag = 1
url <- create_url(website = site, title = job, location = region, radius = 30, page = 1)
url
## [1] "https://www.dice.com/jobs?q=Data+Analyst&l=NY&radius=30&startPage=1&jobs"
#site = JOB_WEBSITE
#job = "Data+Analyst"
#region = STATE_TWO_LETTERS
#miles = MILES_NUM
#pag = PAG_NUM
num_pages = 92
# COMMENT: Loop over the max number of pages for the job search
for (i in 1:num_pages) {
# TODO: Create a url for the job search
url <- create_url(website = site, title = job, location = region, radius = 30, page = i)
# COMMENT: read the created URL and collects the html code
web_html <- read_html(url)
# COMMENT: If statement to create the first dataframe
if(i == 1) {
# COMMENT: Creates a tibble dataframe extracting information from the html code
job_data <- create_tibble(html = web_html)
}else{
# COMMENT: We add new observation to the first dataframe
df <- create_tibble(html = web_html)
job_data <- bind_rows(job_data, df)
}
# COMMENT: We have to wait a couple of seconds before moving to the next page
Sys.sleep(1.0)
}
head(job_data)
## # A tibble: 6 x 5
## title company city state zipcode
## <chr> <chr> <chr> <chr> <chr>
## 1 Data Analyst Talent Minds Networ… New York … NY 10023
## 2 Data Analyst - Data Mining Harris Corporation Rochester NY 14602
## 3 Business/Data Analyst Morgan Stanley UK L… New York NY 10001
## 4 Data Analyst - MDM Publishers Clearing… Jericho NY 11753
## 5 Data Analyst Intern DST Systems, Inc New York NY 10001
## 6 Data Analyst Matlen Silver New York NY 10036
There are 2,735 jobs for the Data Analyst in NYC. All the data is classified as chaacter. All job postings have a city, title, company, state, and zip code.
summary(job_data)
## title company city
## Length:2714 Length:2714 Length:2714
## Class :character Class :character Class :character
## Mode :character Mode :character Mode :character
## state zipcode
## Length:2714 Length:2714
## Class :character Class :character
## Mode :character Mode :character
write_csv(x = job_data, path = "data/dice.ny.csv")
There is a variety of jobs.
NYC has more data analytics jobs than any other city.
Therefore, removed NYC to see other job areas.
The dashboard has the combination of the three different visualization.
To complete the last task, follow the directions found below. Make sure to screenshot and attach any pictures of the results obtained or any questions asked.
The reliability of the data was described as 39%.
The most jobs are in NYC. Second is Brooklyn and Rochester.
Data Analyst, Data Engineer, Data Architect, and Data Scientist are the most common jobs.
Most of the jobs are in NYC downtown. Similar visualization as the previous.