在类错误之外拆包值

Question

I am trying to read in a csv file data and store the data using a class. My variables are not defined in the file directly, but as an input from the csv file. I want to read the Line Ground as an input for the class Building_Storey and split the line using the class method from_st .However I receive this error too many values to unpack (expected 4) and the error message missing 3 required positional arguments if I split the line Ground earlier in the code.it seems that he reads the whole line as one string, and gives the first argument to the whole line. I don't know what is the problem with this code.

Input csv file:

TABLE;BuildingStorey;
GbxmlID;Name;Level;Internal Height;
F0;GroundFloor;0;3.7
F1;FirstFloor;4;3.7
F2;SecondFloor;16;8

The code :

with open('file.csv', 'r')as fp:
    copy = fp.readlines()
    print(copy)
    l = 0
    for line in copy:
        l = l + 1
        if l == 3:
            if 'GroundFloor' in line:
                Ground = line
                print(Ground) 

class Building_Storey:
    def __init__(self, GbxmlID, Name, Level, Internal_Height):

        self.GbxmlID = GbxmlID
        self.Name = Name
        self.Level = Level
        self.Internal_Height = Internal_Height

    @classmethod
    def from_st(cls, Story_st):
        GbxmlID, Name, Level, Internal_Height = Story_st.split(';')
        return cls(GbxmlID, Name, Level, Internal_Height)

Groundfloor = Building_Storey.from_st(Ground)  
print(Groundfloor.GbxmlID)
print(Groundfloor.Name)
print(Groundfloor.Level)
print(Groundfloor.Internal_Height)

Output should be:

  F0;GroundFloor;0;3.7;;;;;;;  # the line I want to read
  GroundFloor.GbxmlID = F0
  GroundFloor.Name = GroundFloor
  GroundFloor.Level = 0
  GroundFloor.Internal_Height = 3.7

Answer 1

You could skip the first two "header" lines and then read each line in using Python's csv library to automatically split the text into a list of values per row. If the list contains 4 entries, pass the values directly to your class using * to pass each list element as an argument to your class:

import csv

class Building_Storey:
    def __init__(self, GbxmlID, Name, Level, Internal_Height):
        self.GbxmlID = GbxmlID
        self.Name = Name
        self.Level = Level
        self.Internal_Height = Internal_Height

with open('file.csv', newline='') as f_file:    
    csv_file = csv.reader(f_file, delimiter=';')
    header_1 = next(csv_file)
    header_2 = next(csv_file)

    for row in csv_file:
        if len(row) == 4:
            floor = Building_Storey(*row)
            print("ID: {}, Name: {}, Level: {}, Height: {}".format(floor.GbxmlID, floor.Name, floor.Level, floor.Internal_Height))

This would display:

ID: F0, Name: GroundFloor, Level: 0, Height: 3.7
ID: F1, Name: FirstFloor, Level: 4, Height: 3.7
ID: F2, Name: SecondFloor, Level: 16, Height: 8