Age-tenure graph for all prime ministers of Sweden (more web-scraping with rvest, then mostly tidy but also some base R)

swe-pm.R

#webscraping wiki to create a age-tenure graph of Swedish PMs
#inspired by https://gist.github.com/acoppock

library(rvest)
library(tidyverse)
library(stringr)
library(lubridate)
library(ggrepel)
library(stringr)

# lets scrape data from wiki
df <- read_html("https://en.wikipedia.org/wiki/List_of_Prime_Ministers_of_Sweden") %>%
  html_nodes(xpath = '//*[@id="mw-content-text"]/div/table[2]') %>%
  purrr::pluck(1) %>% 
  html_table(fill= TRUE)

head(df)

#that went so so...

# remove and rename cols, don't know how do to this "tidy" 
df[1] <- NULL
colnames(df) = df[1, ] # the first row will be the header
df = df[-1, ] 

names(df)[3] <- "term_start"
names(df)[4] <- "term_end"

# tidy from now one

df <- df %>% 
  mutate(name = sub("\\(.*", "", `Name(Birth–Death)`), 
         born = as.numeric(sub("\\D*(\\d{4}).*", "\\1", `Name(Birth–Death)`)),
         term_start = str_replace_all(term_start, "\\[1]|\\[2]", ""),
         #term_end = str_replace_all(term_end, "\\[1]|\\[2]", ""),
         term_start = as.numeric(str_sub(term_start, start = -4)), 
         term_end = lead(term_start),
         term_end = if_else(is.na(term_end), year(today()), term_end),
         parti = `Political Party`,
         parti  = ifelse(name=="Olof Palme", "Social Democrats", parti),
         parti  = ifelse(parti=="Moderate Party(Alliance for Sweden)" | parti == "General Electoral League",
                         "Moderate Party", parti), 
         parti  = ifelse(parti=="Freeminded People's Party", "People's Party", parti),
         parti  = ifelse(parti=="Farmers' League", "Centre Party", parti), 
         pm_num =  1:length(name)) %>% 
  select(name, born, term_start, term_end, parti, pm_num) %>% 
  gather(key, year, term_start, term_end) %>% 
  mutate(age = year - born,
         torch = if_else(key == "term_start", pm_num, as.integer(pm_num + 1))
         ) 
  
label_df <- df %>% filter(key == "term_start")

cols <- c("Social Democrats" = "#cb181d","Moderate Party" = "#084594","Centre Party" = "#4daf4a", 
          "People's Party" = "#2b8cbe", "Liberal Coalition Party" = "#7bccc4", 
          "Independent" = "#807dba", "National Party" = "#6a3d9a")
breaks <- c("Social Democrats", "Moderate Party", "Centre Party", "People's Party", 
              "Liberal Coalition Party", "Independent", "National Party")
#labs <- c("Social Democrats" = "Socialdemokraterna","Moderate Party" = "Moderaterna",
 #         "Centre Party" = "Centerpartiet", "People's Party" = "Folkpartiet", 
  #        "Liberal Coalition Party" = "Liberala Samlingspartiet", "Independent" = "Partilös", 
   #       "National Party" = "Nationella partiet")

ggplot(df, aes(x = year, y = age, group = pm_num)) +
  geom_point(aes(color = parti), size = 2) +
  geom_line(aes(color = parti), size = 1) +
  geom_text_repel(data = label_df, aes(label = name), size = 3, nudge_y = -1) +
  scale_color_manual(name ="Party",
                    values = cols,
                    breaks = breaks
                    #labels = labs
                    ) +
  geom_line(aes(group = torch), linetype = "dotted", alpha = 0.5) +
  theme_classic() +
  ylab("Age")+
  xlab("Year") +
  labs(title = "How old was the Swedish Prime Minister?",
       subtitle = "Code at: https://gist.github.com/tannenberg", 
       caption = "Source: en.wikipedia.org/wiki/List_of_Prime_Ministers_of_Sweden")