Python 3 fix all errors please:

#This program reads a file containing a food web and identifies the relationships between the organisms

import sys

#Parameters: N/A #Returns: Name of the file def commandline_arg(): #If user does not provide a command line argument, let user type in file name if len(sys.argv) == 1: filename = input("Enter the name of a file: ") #If file name does not exist, display error message try: inf = open(filename, "r") except IOError: print("Error: File not found.") quit() #If user provides one command line argument, open file elif len(sys.argv) == 2: filename = sys.argv[1] #If file name does not exist, display error message try: inf = open(filename, "r") except IOError: print("Error: File not found.") quit() #If user provides more than one command line argument, display error message elif len(sys.argv) > 2: print("Error: More than one command line argument entered.") quit() return filename

#Create a dictionary to store predator/prey relationships #Parameters: The name of the file input by the user #Returns: A dictionary containing predator-prey relationships def dictionary(filename): pred_prey_dict = {} for line in filename: #Create empty list to store prey prey_List = [] line = line.rstrip() predator, prey = line.split("eats") prey_List.append(prey) #If predator in dictionary if predator in pred_prey_dict: for prey in prey_List: pred_prey_dict[predator].append(prey) #If predator not in dictionary else: pred_prey_dict[predator] = prey_List #Close the file filename.close return pred_prey_dict

#Lists what each predator eats #Parameters: A dictionary containing predator-prey relationships #Returns: N/A def foodchainOutput(dictionary): print("Predators and Prey:") for pred in dictionary: valueList = dictionary[pred] #If the predator eats one thing, format the string accordingly if len(dictionary[pred]) == 1: print(pred+"eats"+valueList[0]) #If the predator eats two things, place an 'and' between the prey elif len(dictionary[pred]) == 2: print(pred+"eats"+valueList[0]+" and"+valueList[1]) #If the predator eats more than two things, format the string accordingly elif len(dictionary[pred]) > 2: bound= len(valueList) - 2 prey = "" #Place a comma between any prey that aren't the last two prey for value in range(bound): prey+=valueList[value]+"," #Place an 'and' between the last two prey prey+=valueList[len(valueList)-2]+" and"+valueList[len(valueList)-1] print(pred+"eats"+prey)

#Identifies the apex predators in a given food web #Parameters: A dictionary containing predator-prey relationships #Returns: A list of apex predators in the food web def apexPredators(dictionary): print(" Apex Predators:") #Create empty lists for predators, prey, and apex predators predator_List = [] prey_List =[] apexPredator_List = [] #Fill predator list with predators from the dictionary for pred in dictionary: predator_List.append(pred.strip()) #Fill prey list with prey from the dictionary for prey in dictionary[pred]: prey_List.append(prey.strip()) #Determine if predator appears in prey list #Determine if predator already appears in apex predator list #Add predator to apex predator list if not in both lists for pred in predator_List: if pred not in prey_List and pred not in apexPredator_List: apexPredator_List.append(pred) return apexPredator_List

#Identifies the producers in a given food web #Parameters: A dictionary containing predator-prey relationships #Returns: A list of producers in the food web def producers(dictionary): print(" Producers:") #Create empty lists for predators, prey, and producers predator_List = [] prey_List =[] producer_List = [] #Fill predator list with predators from the dictionary for pred in dictionary: predator_List.append(pred.strip()) #Fill prey list with prey from the dictionary for prey in dictionary[pred]: prey_List.append(prey.strip()) #Determine if prey appears in predator list #Determine if prey already appears in producer list #Add prey to producer list if not in both lists for prey in prey_List: if prey not in predator_List and prey not in producer_List: producer_List.append(prey) return producer_List

#Identifies the most flexible eaters in a given food web #Parameters: A dictionary containing predator-prey relationships #Returns: A list of the most flexible eaters in the food web def flexibleEaters(dictionary): print(" Most flexible eaters:") #Create empty list to store amount of different prey eaten biggest_length = 0 length_List = [] #Determine the largest amount of different prey eaten by any predator for pred in dictionary: if len(dictionary[pred]) > biggest_length: biggest_length = len(dictionary[pred]) #Add any predator that eats the same amount of different prey to the list for pred in dictionary: if len(dictionary[pred]) == biggest_length: length_List.append(pred) return length_List

#Identifies the tastiest organisms in a given food web #Parameters: A dictionary containing predator-prey relationships #Returns: A list of the tastiest organisms in a given food web def tastiest(dictionary): print(" Tastiest:") #Create empty dictionary to store prey as keys and how many predators #eat them as values tastiest_Dict = {} for pred in dictionary: for prey in dictionary[pred]: #If prey in dictionary, increase count by 1 if prey in tastiest_Dict: tastiest_Dict[prey] = tastiest_Dict[prey] + 1 #If prey not in dictionary, add prey with a count of 1 else: tastiest_Dict[prey] = 1 #Create an empty list to store the tastiest organisms tastiest_List = [] #Find the biggest number of different predators that eat the same prey maxVal = max(tastiest_Dict.values()) for prey in tastiest_Dict: #Add any prey that is eaten by the same number of different predators to the #list of tastiest organisms if tastiest_Dict[prey] == maxVal: tastiest_List.append(prey) return tastiest_List #Computes the heights of organisms in a given food web #Parameters: A dictionary containing predator-prey relationships #Returns: A dictionary containing predator and prey heights def height(dictionary): print(" Heights:") height_Dict = {} animal_List = [] #Fill predator list with predators from the dictionary for pred in dictionary: animal_List.append(pred.strip()) for prey in dictionary[pred]: if prey not in animal_List: animal_List.append(prey.strip()) for animal in animal_List: height_Dict[animal] = 0 print(height_Dict) change = 1 while change == 1: change = 0 for pred in dictionary: for prey in dictionary[pred]: if height_Dict[pred]

def main():

filename = commandline_arg()

#Open the file inf = open(filename, "r")

#Create a dictionary from a file pred_prey_dict = dictionary(inf) #List what each predator eats foodchainOutput(pred_prey_dict)

#Identify the apex predators apex_P_List = apexPredators(pred_prey_dict) for a_pred in apex_P_List: print(a_pred)

#Identify the producers prod_List = producers(pred_prey_dict) for prod in prod_List: print(prod)

#Identify the most flexible eaters flex_List = flexibleEaters(pred_prey_dict) for flex_eat in flex_List: print(flex_eat)

#Identify the tastiest organisms tastiest_List = tastiest(pred_prey_dict) for tastiest_org in tastiest_List: print(tastiest_org) #Determine the height of every organism height(pred_prey_dict)

main()

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ OUTPUT SHOULD BE +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Predators and Prey: Bird eats Crab, Limpets, Mussels, Prawn and Whelk Crab eats Limpets and Mussels Fish eats Prawn Limpets eats Seaweed Lobster eats Crab, Limpets, Mussels and Whelk Mussels eats Phytoplankton and Zooplankton Prawn eats Zooplankton Whelk eats Limpets and Mussels Zooplankton eats Phytoplankton Apex Predators: Bird, Fish and Lobster Producers: Phytoplankton and Seaweed Most Flexible Eaters: Bird Tastiest: Limpets and Mussels Heights: Bird: 4 Crab: 3 Fish: 3 Limpets: 1 Lobster: 4 Mussels: 2 Phytoplankton: 0 Prawn: 2 Seaweed: 0 Whelk: 3 Zooplankton: 1 

======================

ERROR THAT OCCURS:

CSV:

Traceback (most recent call last) File "assignment4.py", line 234, in main) File "assignment4.py", line 231, in main 1c File "assignment4.py", line 193, in height if height-Dict [pred] height-Dict [prey]