how_old_is_the_president

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

pres_terms <- 
  read_html("https://www.presidentsusa.net/presvplist.html") %>%
  html_nodes("table") %>%
  pluck(1) %>%
  html_table(header = TRUE, fill = TRUE) %>%
  `[`(-46,c(1:3)) %>%
  mutate(President = str_remove(President, "&nbsp"),
         President = str_remove(President, "[[:digit:]]+"),
         President = str_remove(President, "^\\.+|\\.[^.]*$"),
         President = str_trim(President),
         term_start = mdy(`Term Began`),
         term_end = mdy(`Term Ended`),
         term_end = if_else(is.na(term_end), today(), term_end),
         pres_num = 1:45) %>%
  select(President, term_start, term_end, pres_num)

pres_lives <- 
  read_html("https://www.presidentsusa.net/birth.html") %>%
  html_nodes("table") %>%
  pluck(1) %>%
  html_table(header = TRUE, fill = TRUE) %>%
  mutate(birthdate = mdy(`Birth Date`),
         President = str_trim(President),
         President = recode(President, "Franklin Roosevelt" = "Franklin D. Roosevelt",
                            "James A. Garfield" = "James Garfield")) %>%
  select(President, birthdate)
         
presidents <- 
  full_join(pres_terms, pres_lives) %>%
  gather(key, date, term_start, term_end) %>%
  mutate(age = as.duration(date - birthdate) / dyears(1),
         torch = if_else(key == "term_start", pres_num, as.integer(pres_num + 1))) 

label_df <- presidents %>% filter(key == "term_start")

g <- 
ggplot(presidents, aes(x = date, y = age, group = President)) +
  geom_point(aes(color = age), size = 2) +
  geom_line(aes(color = age), size = 1) +
  geom_text_repel(data = label_df, aes(label = President), size = 2, nudge_y = -1) +
  scale_color_gradient(low = "yellow", high = "black") +
  geom_line(aes(group = torch), linetype = "dotted", alpha = 0.3) +
  theme_bw() +
  theme(axis.title = element_blank(),
        legend.position = "none") +
  labs(title = "How old is the US President?",
       subtitle = "Code and Data: https://gist.github.com/acoppock",
       caption = "Source: www.presidentsusa.net")

g