Add and re-arrange comments in comparison.py

app/calculation/comparison.py

@@ -1,21 +1,23 @@
 import random
 
+# This function takes the amont of CO2 emitted from a jet flight, randomly selects a comparison, and then outputs a string that
+# gets addended to the end of the tweet.
+
 def get_emissions_comparison_text(metric_tons_co2_emitted):
   comparisons = ['tree_comparison', 'LA_NY_drive_comparison', 'average_american_emissions_comparison']
   selection = random.choice(comparisons)
   if selection == 'tree_comparison':
     #calculating how many trees are needed to absorb metric_tons_co2_emitted
-    #from arbor day foundation: a mature tree absorbs 48 lbs CO2 per year = 0.02 mt CO2
-
-    annual_tree_absorption_mt = 0.02
+
+    annual_tree_absorption_mt = 0.02 #from arbor day foundation: a mature tree absorbs 48 lbs CO2 per year = 0.02 mt CO2
     trees_needed = metric_tons_co2_emitted/annual_tree_absorption_mt
     trees_needed = int(trees_needed)
     tree_output = f"It will take {trees_needed} tree{ '' if trees_needed == 1 else 's' } approximately 1 year to remove this CO2 from the atmosphere."
 
     return tree_output
 
   elif selection == 'LA_NY_drive_comparison':
-    #driving from LA to NY comparison, 2200lbs CO2 = 0.997 mt
+    #one trip from LA to NY emits 2200lbs CO2 = 0.997 mt CO2
     #Assumptions: compact car, using E10 fuel, there are 3,396 km between LA and NY
 
     trip_emissions_mt = 0.997
@@ -31,12 +33,15 @@ def get_emissions_comparison_text(metric_tons_co2_emitted):
 
     american_emissions_mt = 14.5
     years_needed = metric_tons_co2_emitted/american_emissions_mt
+    #If it would take an average American less than 1 year to emit the same amount as the jet trip, we want the output
+    # to be in terms of months (ex: 6 months instead of 0.5 years)
     if years_needed <1:
       months_needed = years_needed * 12
       months_needed = int(months_needed)
       months_output = f"It would take an average American {months_needed} month{ '' if months_needed == 1 else 's' } to emit the same amount."
       return months_output
+    #If it takes longer than a year for an American to emit the same amount as the jet trip, we want the output to be in terms of years.
     else:
       years_needed = round(years_needed,2)
       years_output = f"It would take an average American {years_needed} year{ '' if years_needed == 1 else 's' } to emit the same amount."
-      return years_output
+      return years_output