Question

Complete the function load_trees_from_file() specified in A1.py

It should take as a parameter the name of a file containing a set of trees and return a list containing instances of the Tree class representing all of the trees listed in the file. If the file does not exist, it should print that the file is not found and return None.

You will need to include your Tree class definition from Question 1 in your answer.

Consider the following code fragment:

trees = load_trees_from_file('Trees.txt')
[print(t) for t in trees]

If the file Trees.txt contains the following lines:

Ash,10,150,75,0,0,255,0,30
Oak,12,130,70,0,0,200,0,45

The output will be:

Ash
Oak

class Tree:

class Tree:
def __init__(self,name,length,color_b,color_l,angle): # defining init method
self.name = name
self.length = length
self.color_b = color_b
self.color_l = color_l
self.angle = angle
  
def __str__(self): # defining str method
return self.name
  
def __repr__(self): # defining repr method
return 'Tree("{}", {}, {}, {}, {})'.format(self.name,self.length,self.color_b,self.color_l,self.angle)

Answer 1

Here is the completed code for this problem. Comments are included, go through it, learn how things work and let me know if you have any doubts or if you need anything to change. If you are satisfied with the solution, please rate the answer. Thanks

Note: Please maintain proper code spacing (indentation), just copy the code part and paste it in your compiler/IDE directly, no modifications required.

#code

class Tree:
    def __init__(self, name, length, color_b, color_l, angle):  # defining init method
        self.name = name
        self.length = length
        self.color_b = color_b
        self.color_l = color_l
        self.angle = angle

    def __str__(self):  # defining str method
        return self.name

    def __repr__(self):  # defining repr method
        return 'Tree("{}", {}, {}, {}, {})'.format(self.name, self.length, self.color_b, self.color_l, self.angle)



#required method
def load_trees_from_file(filename):
    #opening file inside a try-except block
    try:
        file=open(filename,'r') #opening file in read mode
        #creating an empty list
        trees=[]
        #looping through each line
        for line in file:
            #stripping blanks/newlines from either ends and splitting line by ','
            fields=line.strip().split(',')
            #checking if resultant list's length is 9
            if len(fields)==9:
                #taking first value as name
                name=fields[0]
                #parsing second value as integer for length
                length=int(fields[1])
                #creating a 2 element tuple using the next three values as integers for
                #representing r,g,b values for color_b (assuming that is how you store color in Tree class)
                color_b=(int(fields[2]),int(fields[3]),int(fields[4]))
                #doing the same with next three values for color_l
                color_l = (int(fields[5]), int(fields[6]), int(fields[7]))
                #fetching next value as integer angle
                angle=int(fields[8])
                #creating a Tree with these values, adding to the list
                t=Tree(name,length,color_b,color_l,angle)
                trees.append(t)
        #closing file
        file.close()
        #returning list
        return trees
    except:
        #file not found, displaying error and returning None
        print('file is not found')
        return None