Convert string from text file inorder to plot using matplotlib - python-3.x

Question

I am trying to plot a graph using dates and integers from a text file which looks like this:
However I keep getting this error
Traceback (most recent call last):
File "C:\Users\Haeshan\Desktop\Comp Sci CC\graph.py", line 21, in
graph()
File "C:\Users\Haeshan\Desktop\Comp Sci CC\graph.py", line 9, in graph
converters = {1: mdates.strpdate2num("%d/%m/%Y")})
File "C:\Users\Haeshan\AppData\Local\Programs\Python\Python35\lib\site-packages\numpy\lib\npyio.py", line 930, in loadtxt
items = [conv(val) for (conv, val) in zip(converters, vals)]
File "C:\Users\Haeshan\AppData\Local\Programs\Python\Python35\lib\site-packages\numpy\lib\npyio.py", line 930, in
items = [conv(val) for (conv, val) in zip(converters, vals)]
File "C:\Users\Haeshan\AppData\Local\Programs\Python\Python35\lib\site-packages\numpy\lib\npyio.py", line 659, in floatconv
return float(x)
ValueError: could not convert string to float: b"['10'"
import matplotlib.pyplot as plt
import numpy as np
import csv
import matplotlib.dates as mdates
def graph():
date, value = np.loadtxt("Scores.txt", delimiter = ",", unpack=True,
converters = {1: mdates.strpdate2num("%d/%m/%Y")})
fig = plt.figure()
ax1 = fig.add_subplot(1,1,1, axisbg ="white")
plt.plot_date(x=date, y=value)
plt.title("Performace")
plt.ylabel("Score")
plt.xlabel("Date")
graph()
Any ideas,
Many thanks

Answer 1

The problem is your first column which has quotation marks. Since you have anyhow define converters I would change it to
converters = {0: (lambda x: int(x)),1: mdates.strpdate2num("%d/%m/%Y")})
UPDATE
Sorry, due to the quotations marks I didn't see the other issues. TBH, I would not use np.loadtxt in this case since you have also the square brackets in each line. In addition you have the issue that you are using Python 3 where strings are unicode and not bytes anymore, but loadtxt is going for bytes (thus the b in front of your line).
My suggestion is to read it in line by line and parse each line, e.g.
dates,values = list(),list()
formater = mdates.strpdate2num("%d/%m/%Y")
with open("Scores.txt",'r',newline='\n') as input_file:
for line in input_file:
# Remove the square brackets, quotation marks and newlines (if necessary)
# Be aware that this will also kill all square brackets and quotations marks in your line
entries = line.replace('[','').replace(']','').replace("'",'').replace('\n','').split(',')
values.append(int(entries[0]))
dates.append(formater(entries[1]))