Matplotlib: blank plot and window won't close

Question

I'm trying to plot a curve using the data from a csv file using:

import matplotlib.pyplot as plt
from csv import reader

with open('transmission_curve_HST_ACS_HRC.F606W.csv', 'rw') as f:
         data = list(reader(f))
         wavelength_list = [i[0] for i in data[1::]]
         percentage = [i[1] for i in data[1::]]

plt.plot(wavelength_list, percentage)
plt.show()

But all it make is opening a completely blank window and I can't close it unless I close the terminal.

The csv file looks like this:

4565,"0,00003434405472044760"
4566,"0,00004045191689260860"
4567,"0,00004656394357747830"
4568,"0,00005267963655205460"
4569,"0,00005879949856084820"

Do you have any idea why?

Answer 1

You need to modify three things in your code:

1. Change 'rw' to 'r' when you read from the file
2. Correct the way you iterate over data
3. Convert the numbers from the second column to float

---

import matplotlib.pyplot as plt
from csv import reader

with open('transmission_curve_HST_ACS_HRC.F606W.csv', 'r') as f:
         data = list(reader(f))
         wavelength_list = [i[0] for i in data]
         percentage = [float(str(i[1]).replace(',','.')) for i in data]

plt.plot(wavelength_list, percentage)
plt.show()

Content of the csv file:

4564,"0,00002824029270045730"
4565,"0,00003434405472044760"
4566,"0,00004045191689260860"
4567,"0,00004656394357747830"
4568,"0,00005267963655205460"
4569,"0,00005879949856084820"