Turn A List to a Float That Can Be Divided

Question

I've been trying super hard to make a currency converter for the world. One of the many problems I've been facing is that my currency converter wouldn't figure out the exchange rate itself; YOU had to. But of course, I figured it out.

But my question is: I got the exchange rate for EURO, but it's a list, and I need it a float to do the calculation. How would I do that?

Here is what I've tried:

euro_exchange = float(str(tree.xpath('//div[@class="price"]/text()')))
######################################################################
euro_exchange = tree.xpath('//div[@class="price"]/text()')

float(str(euro_exchange)
################################################################
euro_exchange = float(tree.xpath('//div[@class="price"]/text()')

You get the pattern. When I tried euro_exchange = float(str(tree.xpath('//div[@class="price"]/text()'))), it says (I'm using TkInter, BTW):

Exception in Tkinter callback
Traceback (most recent call last):
  File "/usr/lib/python3.5/tkinter/__init__.py", line 1562, in __call__
    return self.func(*args)
  File "/home/jboyadvance/Documents/Code/Python/Currency Converter/Alpha2/main.py", line 21, in usd_callback
    euro_exchange = float(str(tree.xpath('//div[@class="price"]/text()')))
ValueError: could not convert string to float: "['1.1394']"

and when I tried euro_exchange = tree.xpath('//div[@class="price"]/text()') float(str(euro_exchange) I got the same results.

When I tried euro_exchange = float(tree.xpath('//div[@class="price"]/text()'):

Exception in Tkinter callback
Traceback (most recent call last):
  File "/usr/lib/python3.5/tkinter/__init__.py", line 1562, in __call__
    return self.func(*args)
  File "/home/jboyadvance/Documents/Code/Python/Currency Converter/Alpha2/main.py", line 21, in usd_callback
    euro_exchange = float(tree.xpath('//div[@class="price"]/text()'))
TypeError: float() argument must be a string or a number, not 'list'

And here's the source code:

import tkinter as tk
from lxml import html
import requests

window = tk.Tk()

window.title("Currency Converter")

window.geometry("500x500")

window.configure(bg="#900C3F")

# window.wm_iconbitmap("penny.ico")

page = requests.get('https://www.bloomberg.com/quote/EURUSD:CUR')
tree = html.fromstring(page.content)


def usd_callback():
    usd_amount = float(ent_usd.get())
    euro_exchange = float(str(tree.xpath('//div[@class="price"]/text()')))

    euro_amount = usd_amount / euro_exchange

    lbl_euros.config(text="Euro Amount: %.2f€" % euro_amount)


lbl_usd = tk.Label(window, text="Enter the USD ($) here:", bg="#900C3F", font="#FFFFFF")
ent_usd = tk.Entry(window)

btn_usd = tk.Button(window, text="Convert", command=usd_callback, bg="#FFFFFF", font="#FFFFFF")

lbl_euros = tk.Label(window)

lbl_usd.pack()
ent_usd.pack()

btn_usd.pack()

window.mainloop()

Any help would be gladly appreciated! Thank you!!

Answer 1

You need to convert the first element from the return value from xpath :

euro_exchange = tree.xpath('//div[@class="price"]/text()')
euro_exchange = float(str(euro_exchange[0]))