Definining functions

double <- function(number) {
  number*2
}

The name of the function is double() and it takes one argument number.

double(number = 3)

## [1] 6

double(3)

## [1] 6

Setting a default argument

double <- function(number = 5) {
  number*2
}

double()

## [1] 10

Having multiple arguments

multiply <- function(number, by) {
  number*by
}

multiply(number = 10, by = 3)

## [1] 30

Goal

Can we get the top 50 highest ranked feature movies for any year?

Featured Movies

Scraping the 2010 movie titles

library(tidyverse)
library(rvest)
page <- "https://www.imdb.com/search/title/?title_type=feature&year=2010-01-01,2010-12-31&sort=user_rating,desc"
read_html(page) %>% 
  html_nodes(".lister-item-header a") %>% 
  html_text()

##  [1] "Lebensraum/Living Space"                                                    
##  [2] "Revolver: Poor Boyz"                                                        
##  [3] "Bohlol Dana - A Sage of Baghdad"                                            
##  [4] "Tebaatusasula"                                                              
##  [5] "Townbiz"                                                                    
##  [6] "Die Haushaltshilfe"                                                         
##  [7] "Min pinlige familie og mutantdræbersneglene"                                
##  [8] "Dhinveynugehithaamaigaa"                                                    
##  [9] "It's Always Sunny in Philadelphia: Cast & Creators Live at the Paley Center"
## [10] "DranDeh"                                                                    
## [11] "Truth & Life Dramatized Audio Bible"                                        
## [12] "Les palmiers blessés"                                                       
## [13] "Staying Gold"                                                               
## [14] "Love Equation"                                                              
## [15] "The Final Journey"                                                          
## [16] "The Ballad of Frankie Silver"                                               
## [17] "Les Misérables in Concert: The 25th Anniversary"                            
## [18] "Doraleous and Associates"                                                   
## [19] "A3D Ayumi Hamasaki Arena Tour 2009 A: Next Level"                           
## [20] "Kisses, Chloe"                                                              
## [21] "Barriere"                                                                   
## [22] "Unbelehrbar"                                                                
## [23] "New Kids on the Block: Coming Home"                                         
## [24] "In Focus"                                                                   
## [25] "Inception"                                                                  
## [26] "Nobody Smiling"                                                             
## [27] "American Falls"                                                             
## [28] "The Clock"                                                                  
## [29] "Heroes Crossing"                                                            
## [30] "The Corners"                                                                
## [31] "The Toll"                                                                   
## [32] "Rat Rod Rockers!"                                                           
## [33] "Urban Wolf"                                                                 
## [34] "Grand Slammed"                                                              
## [35] "Jen"                                                                        
## [36] "Supériorité"                                                                
## [37] "The New Normal"                                                             
## [38] "Freedom Hills"                                                              
## [39] "Vecinos"                                                                    
## [40] "Sesame Street: C is for Cookie Monster"                                     
## [41] "Green Day: 21st Century Breakdown"                                          
## [42] "Life of the Party: Vol. II"                                                 
## [43] "National Theatre Live: Nation"                                              
## [44] "The Wizard of Agni"                                                         
## [45] "Slednecks 13"                                                               
## [46] "Writer's Block"                                                             
## [47] "Black Eyed Peas 3D: Live"                                                   
## [48] "Step Away from the Stone"                                                   
## [49] "The Beekeepers"                                                             
## [50] "Out of Focus"

Scraping the 2011 movie titles

page <- "https://www.imdb.com/search/title/?title_type=feature&year=2011-01-01,2011-12-31&sort=user_rating,desc"
read_html(page) %>% 
  html_nodes(".lister-item-header a") %>% 
  html_text()

##  [1] "Ashi Fasli Nanachi Tang"                                                 
##  [2] "Imported Affairs"                                                        
##  [3] "Deswa"                                                                   
##  [4] "Ka Oryang"                                                               
##  [5] "Year of the Rat"                                                         
##  [6] "Love on a Leash"                                                         
##  [7] "Losers in Love"                                                          
##  [8] "The Script: Homecoming"                                                  
##  [9] "Rescue Team"                                                             
## [10] "Howling at the Moon"                                                     
## [11] "Sans pudeur ni morale"                                                   
## [12] "Kill Bill: The Whole Bloody Affair"                                      
## [13] "Virtual Trek Wildlife Park"                                              
## [14] "The Nutcracker and the Mouse King"                                       
## [15] "Flashback"                                                               
## [16] "Myth & Mystery"                                                          
## [17] "American Actor"                                                          
## [18] "Blood Eclipse"                                                           
## [19] "So Much Pain So in Love"                                                 
## [20] "The Phantom of the Opera at the Royal Albert Hall"                       
## [21] "The Second Times of Troubles"                                            
## [22] "At the Jersey Shore"                                                     
## [23] "Stalemate"                                                               
## [24] "Gente mala del norte"                                                    
## [25] "Mr. Plinkett's Indiana Jones and the Kingdom of the Crystal Skull Review"
## [26] "S.a.l.i.m & Co.'s Café"                                                  
## [27] "Villa Vevrier"                                                           
## [28] "Big Weekend"                                                             
## [29] "The Racket Boys"                                                         
## [30] "The Soft Touch"                                                          
## [31] "Men's Egg Drummers"                                                      
## [32] "Frankenstein"                                                            
## [33] "Egression"                                                               
## [34] "She's Out of His Mind"                                                   
## [35] "Stan"                                                                    
## [36] "Faust Sonnengesang"                                                      
## [37] "Röhrls Katze"                                                            
## [38] "Much Ado About Nothing"                                                  
## [39] "Marija's Own"                                                            
## [40] "Bettada Jeeva"                                                           
## [41] "Deadmau5 Live @ Earls Court"                                             
## [42] "40-Life"                                                                 
## [43] "Payin' the Price"                                                        
## [44] "Acharya"                                                                 
## [45] "Nine Lives: A Musical Adaptation Live"                                   
## [46] "Tangled Up in Blue"                                                      
## [47] "South of Southern"                                                       
## [48] "Chocolate"                                                               
## [49] "Taken in"                                                                
## [50] "Erase una vez en Bolivia"

All we are changing is the date in the URL.

We cannot just keep copying and pasting our code for each year. It gets tiring!!!

Whenever you catch yourself copying and pasting code and only modifying a tiny part (e.g. year in the URL), write a function to automate the process. The tiny part that needs the modification can be the argument of the function.

scrape_movie_title <- function(year) {
  page <- paste0("https://www.imdb.com/search/title/?title_type=feature&year=", year, "-01-01,", year, "-12-31&sort=user_rating,desc")
read_html(page) %>% 
  html_nodes(".lister-item-header a") %>% 
  html_text()
}

scrape_movie_title(2002)

##  [1] "Venganza"                                            
##  [2] "Welcome to San Pedro"                                
##  [3] "The Cloud of Unknowing"                              
##  [4] "Americanos"                                          
##  [5] "Punarjani"                                           
##  [6] "Ayodhya Ramayya"                                     
##  [7] "JJ Cale in Session"                                  
##  [8] "Papsajt"                                             
##  [9] "Mage Wam Atha"                                       
## [10] "Check Mate"                                          
## [11] "Bakshis"                                             
## [12] "Destiny 101"                                         
## [13] "Engaging Peter"                                      
## [14] "A Mero Hajur"                                        
## [15] "Regarding Penelope's Wake"                           
## [16] "Montagna con Forza"                                  
## [17] "Book of Danny"                                       
## [18] "2 Fläschchen"                                        
## [19] "Dreaming in Black and White"                         
## [20] "Until Morning"                                       
## [21] "The Wishing Stone"                                   
## [22] "Only in Hollywood"                                   
## [23] "Living with the Fosters"                             
## [24] "Someone Is Sleeping in My Pain: An East-West Macbeth"
## [25] "Blackmailing Santa"                                  
## [26] "The Lord of the Rings: The Two Towers"               
## [27] "My Father's Daughter"                                
## [28] "Phulkumar"                                           
## [29] "West Bank Brooklyn"                                  
## [30] "My Brother's Light"                                  
## [31] "Matir Moina"                                         
## [32] "City of God"                                         
## [33] "Manmandir"                                           
## [34] "Khandan"                                             
## [35] "Simhadriya Simha"                                    
## [36] "Crackaparkz"                                         
## [37] "Appu"                                                
## [38] "Developing Sheldon"                                  
## [39] "Le Chant de la Noria"                                
## [40] "Who the Hell Is Bobby Roos?"                         
## [41] "Mutual Admiration Society"                           
## [42] "Filantropica"                                        
## [43] "Sexgunsmoney@20"                                     
## [44] "The Pianist"                                         
## [45] "Nomad"                                               
## [46] "Kanyadaan"                                           
## [47] "Yuva Ratna"                                          
## [48] "Peggy and Fred in Hell: The Complete Cycle"          
## [49] "Enki-Benki"                                          
## [50] "Yearbook"