如何为特定键值创建新字典？

Question

For each element in the file (row), I need to create a new dictionary where the keys are the property names from the header row (Atomic Number, Atomic Name, etc) and the values are the values for each property. However, I cannot create specific dictionary for each element. My output is totally different from the given output. That's an assignment therefore, getting the whole code doesn't make sense. Can you tell me what my mistake is, how I can fix it?

This is my short raw data of the inputted file:

Chemical symbol     Name    Origin of symbol    Atomic Number   Atomic mass     Density Melting point   Boiling point   Year of discovery   Discoverer
Ac  Actinium        89  227.0278    10.07   1047    3197    1899    Debierne
Ag  Silver  Latin Argentum  47  107.8682    10.49   961.9   2212    prehistoric     unknown
Al  Aluminium       13  26.981539   2.70    660.5   2467    1825    Oersted
Am  Americium       95  243.0614    13.67   994     2607    1944    Seaborg
Ar  Argon       18  39.948  1.66 g/l    -189.4  -185.9  1894    Ramsay and Rayleigh

My short output is like this:

|Chemical symbol    Name    Origin of symbol    Atomic Number   Atomic mass     Density Melting point   Boiling point   Year of discovery   Discoverer : Co     Cobalt      27  58.9332     8.89    1495    2870    1735    Brandt
|Chemical symbol    Name    Origin of symbol    Atomic Number   Atomic mass     Density Melting point   Boiling point   Year of discovery   Discoverer : Cr     Chromium        24  51.9961     7.14    1857    2482    1797    Vauquelin 

---

However, the desired output is like this:

    |Element Name       :   Hydrogen
    |Chemical symbol    :   H
    |Origin of symbol   :   
    |Atomic Number      :   1.00
    |Atomic mass        :   1.01
    |Density            :   0.084 g/l 
    |Melting point      :   -259.1
    |Boiling point      :   -252.9
    |Year of discovery  :    1766
    |Discoverer         :   Cavendish

---

Here is my code:

class Element:
    def __init__(self, eName, elementData):
        self.__eName = str(eName)
        self.elementData = dict(elementData)
    
        for e in self.elementData:
            if isinstance(self.elementData[e],int) or isinstance(self.elementData[e],float):
                float(elementData[e])

    def __eq__(self,other):
        if self.__eName == other.__eName:
            return True
        else:
            return False
            
    def __lt__(self, other):
        if self.elementData['Atomic Number'] < other.elementData['Atomic Number']:
            return True
        else:
            return False
        
    def __repr__(self):
        for k in self.elementData:
            return "|"+ k +' : '+ self.elementData[k]+'\n'
        
    def get_property(self, property):
        return self.elementData[property]

---

import numpy as np
from Element import *

file = np.loadtxt("data.txt",dtype = "str", delimiter = "|t")

dict1 = {}

for i in range(1,len(file)):
    for col in np.row_stack((file[0],file[i])).T:
        key = col[0]
        dict1[key] = col[1]
    
    el_Name = dict1[key]
    elem = Element(el_Name, dict1)
    print(elem)

Answer 1

The delimiter character ( |t ) in this line is incorrect:

file = np.loadtxt("data.txt",dtype = "str", delimiter = "|t")

it should be ( \t ) to represent a tab character ( see docs ):

file = np.loadtxt("data.txt",dtype = "str", delimiter = "\t")

With the incorrect delimiter, each row is read as a single column. You can see the consequences of this by printing the value of dict1 , which reveals there is only a single key-value pair:

el_Name = dict1[key]
print(dict1)  # print the value of dict1 for debugging/illustration purposes
elem = Element(el_Name, dict1)

output: {'Chemical symbol\tName\tAtomic Number\tAtomic mass\tDensity\tMelting point\tBoiling point\tYear of discovery\tDiscoverer': 'Ac\tActinium\t89\t227.0278\t10.07\t1047\t3197\t1899\tDebierne'}

After fixing the delimiter, the value of dict1 looks like this:

output: {'Chemical symbol': 'Ac', 'Name': 'Actinium', 'Atomic Number': '89', 'Atomic mass': '227.0278', 'Density': '10.07', 'Melting point': '1047', 'Boiling point': '3197', 'Year of discovery': '1899', 'Discoverer': 'Debierne'}

Now there are key-value pairs for each property of the chemical.

---

After fixing that, you might run into another issue in your __repr__ function. It loops over each of the chemical properties, but it returns early in the first iteration of the loop, so you'll only see the first property for each chemical.

    def __repr__(self):
        for k in self.elementData:
            return "|"+ k +' : '+ self.elementData[k]+'\n'  # this returns immediately! we only see the first value from self.elementData

You could fix this by building up the properties one by one, then return outside of the for loop, like this:

    def __repr__(self):
        s = ''
        for k in self.elementData:
            s += "|"+ k +' : '+ self.elementData[k]+'\n'
        return s

---

With those changes my output looks like this:

(I had to remove the 'Origin of symbol' column because of missing values in the example data)

|Chemical symbol : Ac
|Name : Actinium
|Atomic Number : 89
|Atomic mass : 227.0278
|Density : 10.07
|Melting point : 1047
|Boiling point : 3197
|Year of discovery : 1899
|Discoverer : Debierne

Answer 2

Building up on honk's answer .

To get the pretty indentation you initially requested and make a more pythonic dictionary iteration :

def __repr__(self):
       maxKeyLength = max([len(k) for k in self.elementData])
       s = ''
       for key, value in self.elementData.items():
           s += f"|{key:maxKeyLength}  :  {value}\n"
       return s