better error handling and logic error fixing

extract-twitter-accounts.R

@@ -51,7 +51,8 @@ max_count <- "200"
 keep <- c("created_at", "id_str", "text", "retweet_count")
 tweets_full <- data.frame(user=character(), name=character(), created_at=character(), id_str=character(), text=character(), retweet_count=character())
 tweets_complete <- tweets_full
-for(a in 1:nrow(acc_df)) {
+
+for(a in 94:nrow(acc_df)) {
   user <- as.character(acc_df$screenname[a])
   name <- as.character(acc_df$name[a])
   max_id <- "999999999999999999"
@@ -66,63 +67,32 @@ for(a in 1:nrow(acc_df)) {
     
     # At first, work with an temporary tweet-DB
     current <- twitter_api_call(api_url, query, api_params)
+    rm(tweets_temp)
     tweets_temp <- fromJSON(correctJSON(current))
     
-    ## START ERROR HANDLING ##
+    ## START ERROR HANDLING ##   
+    # Empty API output
+    status <- errorEmptyAPI(tweets_temp)
+    if(status == 1) { Sys.sleep(3);error <- error + 1;next}
+    if(status == 2) {break}
     
-    # Check for empty API returns
+    # Contains "error" column
-    status <- length(tweets_temp)
+    status <- errorErrorColumn(tweets_temp)
-    if(status == 0) {
+    if(status == 1) { Sys.sleep(3);error <- error + 1;next}
-      if(error > 2) {
+    if(status == 2) {break}
-        cat("[WARNING] 3x empty API result. Aborting now.\n")
+    
-        break
+    # Check if error code exists
-      }
+    code <- errorCheckCode(tweets_temp) # 0 if no error
-      cat("[WARNING] Empty API result. Trying again.\n")
+    if(code == 34) {  # page does not exist
-      rm(tweets_temp)
+      status <- errorCode34
-      error <- error + 1
+      if(status == 1) { Sys.sleep(3);error <- error + 1;next}
-      Sys.sleep(3)
+      if(status == 2) {break}
+    }
+    if(code == 88) {  # rate limit exceeded
+      wait <- errorCode88()
+      Sys.sleep(wait)
       next
-    }
+    }  
-    
-    # Check if API output contains error fields
-    status <- "error" %in% names(tweets_temp)
-    if(status) {
-      cat("[WARNING] Error in API request:", tweets_temp$error[1],"\n")
-      rm(tweets_temp)
-      break
-    }
-    
-    # Check for other errors, mostly rate limits
-    status <- "errors" %in% names(tweets_temp)
-    if(status) {
-      cat("[WARNING] Error in API request:", tweets_temp$errors[1,1],"\n")
-      status <- tweets_temp$errors[1,2]
-      
-      # "Rate limit exceeded"
-      if(status == 88) {
-        rate_api_url <- "https://api.twitter.com/1.1/application/rate_limit_status.json"
-        rate_query <-c (resources="statuses")
-        resettime <- fromJSON(twitter_api_call(rate_api_url, rate_query, api_params))
-        resettime <- resettime$resources$statuses$`/statuses/user_timeline`$reset
-        curtime <- as.numeric(as.POSIXct(Sys.time()))
-        wait <- round(resettime - curtime + 10)
-        cat("[INFO] Rate limit is exceeded. Now waiting",wait,"seconds.\n")
-        Sys.sleep(wait)
-      }
-      
-      # "Sorry, that page does not exist"
-      if(status == 34) {
-        if(error > 2) {
-          cat("[WARNING] 3x Not existing page. Aborting now.\n")
-          break
-        }
-        error <- error + 1
-      }
-      
-      rm(tweets_temp)
-      Sys.sleep(3)
-      next
-    }
     ## END ERROR HANDLING ##
     
     
@@ -173,7 +143,7 @@ for(a in 1:nrow(acc_df)) {
       rm(old)
       
       tweets_full <- insertRow(tweets_full, tweets_temp)
-      rm(tweets_temp)
+      #rm(tweets_temp)
       break  # End loop because 2013 is reached
     }
     
@@ -184,7 +154,7 @@ for(a in 1:nrow(acc_df)) {
       loop <- loop + 1  # just for stats
       
       tweets_full <- insertRow(tweets_full, tweets_temp)
-      rm(tweets_temp)
+      #rm(tweets_temp)
     }
   } # /repeat
   

functions.R

@@ -2,6 +2,8 @@ require(stringr)
 
 # Replace characters messing up JSON validation (\,\n,^)
 correctJSON <- function(string) {
+  string <- gsub('\\\\\\\\\\"(\\w)', '\\1' , string)
+  string <- gsub('\\\\\\\\\\" ', ' ', string)
   string <- gsub("\\\\{2,}", "", string)
   string <- str_replace_all(string, pattern = "[^[:print:]]", replacement = " ")
   string <- str_replace_all(string, pattern = "&..;", replacement = " ")
@@ -16,3 +18,74 @@ insertRow <- function(existingDF, newrow, r) {
   row.names(existingDF) <- 1:nrow(existingDF)
   return(existingDF)  
 }
+
+## ERROR HANDLING
+
+# Check for empty API returns (0 or 1 or 2)
+errorEmptyAPI <- function(df) {
+  status <- length(df)
+  if(status == 0) {
+    if(error < 3) {
+      cat("[WARNING] Empty API result. Trying again.\n")
+      returncode <- 1
+    }
+    else {
+      cat("[WARNING] 3x empty API result. Aborting now.\n")
+      returncode <- 2
+    } 
+  }
+  else {
+    returncode <- 0
+  }
+  return(returncode)
+}
+
+# Check if API output contains error fields (0 or 2)
+errorErrorColumn <- function(df) {
+  status <- "error" %in% names(df)
+  if(status) {
+    cat("[WARNING] Error in API request:", df$error[1],"\n")
+    returncode <- 2
+  }
+  else {
+    returncode <- 0
+  }
+  return(returncode)
+}
+
+# Check if error codes exist (i.e. 34 or 88)
+errorCheckCode <- function(df) {
+  status <- "errors" %in% names(df)
+  if(status) {
+    cat("[WARNING] Error in API request:", df$errors[1,1],"\n")
+    code <- df$errors[1,2]
+  }
+  else {
+    code <- 0
+  }
+  return(code)
+}
+
+# Handle code 88: rate limit exceeded (wait time)
+errorCode88 <- function() {
+  rate_api_url <- "https://api.twitter.com/1.1/application/rate_limit_status.json"
+  rate_query <- c(resources="statuses")
+  resettime <- fromJSON(twitter_api_call(rate_api_url, rate_query, api_params))
+  resettime <- resettime$resources$statuses$`/statuses/user_timeline`$reset
+  curtime <- as.numeric(as.POSIXct(Sys.time()))
+  wait <- round(resettime - curtime + 10)
+  cat("[INFO] Rate limit is exceeded. Now waiting",wait,"seconds.\n")
+  return(wait)
+}
+
+# Handle code 34: Page does not exist (1 or 2)
+errorCode34 <- function() {
+  if(error > 2) {
+    cat("[WARNING] 3x Not existing page. Aborting now.\n")
+    returncode <- 2
+  }
+  else {
+    returncode <- 1
+  }
+  return(returncode)
+}