How to link a CSV file containing attributes to a Python class?

Question

I've got a class Person which has attributes like name, age, weight, and height. I'm trying to add a function now which reads a CSV file that has these attributes for each person so it can print it out in the end, but I'm struggling to figure out how I can link those two.

So far I've written my read_people function at the bottom, but I don't know where to go from there. How can I link each part of each line to name, age, weight, and height?

"""File for creating Person objects"""

class Person:
    """Defines a Person class, suitable for use in a hospital context.
    Data attributes: name of type str
                     age of type int
                     weight (kg) of type float
                     height (metres) of type float
    Methods: bmi()
             status()
    """

    def __init__(self, name, age, weight, height):
        """Creates a new Person object with a specified name, age, weight, and
        height."""

        self.name = name
        self.age = age
        self.weight = weight
        self.height = height


    def bmi(self):
        """Returns the body mass index of the person"""
        return self.weight / (self.height * self.height)

    def status(self):

        if self.bmi() < 18.5:
            return "Underweight"
        if self.bmi() >= 18.5 and self.bmi() < 25:
            return "Normal"
        if self.bmi() >= 25 and self.bmi() < 30:
            return "Overweight"
        if self.bmi() >= 30:
            return "Obese"


    def __str__(self):
        """Returns the formatted string represent of the Person object"""
        name = self.name
        age = self.age
        bmi = self.bmi()
        status = self.status()
        template = "{0} ({1}) has a bmi of {2:3.2f}. Their status is {3}."
        return template.format(name, age, bmi, status)    




def read_people(csv_filename):

    file = open(csv_filename, "r")    
    for line in file:
        line = line.split(",")   



bods = read_people("people1.csv")
for bod in bods:
    print(bod)

Example of the csv file:

Peter Piper,23,89.4,1.82
Polly Perkins,47,148.8,1.67
Griselda Gribble,92,48,1.45
Ivan Ng,19,59,2.0
Lucy Lovelorn,14,50,1.6
Leslie McWhatsit,70,59.2,1.65

Possible duplicate of [Making objects from a CSV file Python](https://stackoverflow.com/questions/24641894/making-objects-from-a-csv-file-python) — razdi, May 12 '19 at 23:37
I tried doing the example in that post @razdi but I got the error `can't multiply sequence by non-int of type 'str'` — Amanda_C, May 12 '19 at 23:51
Check the line where that error is raised. While reading the variables from the csv, you're probably reading them as strings. Cast them as integers so that any multiplications you might be performing can take place without a hitch — razdi, May 13 '19 at 00:07

Mahmoud Elshahat · Answer 1 · 2019-05-13T00:14:27.673

Try this:

def read_people(csv_filename):
    persons = []  # list for Person objects

    with open(csv_filename, "r") as file:  
        for line in file:
            args = line.split(",")

            for i in range(1, len(args)):  # convert arguments to float
                args[i] = float(args[i])

            persons.append(Person(*args))  # add Person objects to list
    return persons




bods = read_people("people1.csv")
for bod in bods:
    print(bod)
    print()

output:

Griselda Gribble (92.0) has a bmi of 22.83. Their status is Normal.

Ivan Ng (19.0) has a bmi of 14.75. Their status is Underweight.

Lucy Lovelorn (14.0) has a bmi of 19.53. Their status is Normal.

Leslie McWhatsit (70.0) has a bmi of 21.74. Their status is Normal.

score 0 · Answer 2 · answered May 12 '19 at 23:52

0

You are opening a file object in the 'file = open(cvs_filename, "r"). But you are not reading the file.

file = open(cvs_filename, "r")
file_contents = file.readlines()

Will read them into a list of lines to iterate, modify and capture in a different variable, then return the results to the caller.

answered May 12 '19 at 23:52

Matt

29
5

how would I link that to the class Person though – Amanda_C May 13 '19 at 00:04
you would need to split the line into the individual elements and pass them into the class as the parameters. Are we doing homework? – Matt May 13 '19 at 00:09

score 0 · Accepted Answer · answered May 13 '19 at 00:11

Just make sure to cast the variables while creating the objects to make sure it works as expected


import csv

person_list = []

with open('file.csv', 'r') as f:
    reader = csv.reader(f)
    for row in reader:
        person_list.append(Person(row[0], int(row[1]), float(row[2]), float(row[3]))

How to link a CSV file containing attributes to a Python class?

3 Answers3