title: How to plot from .txt file
body: <p>I have a .txt file and would like to plot the data.</p>
  <p>Here my code</p>
  <pre><code>import matplotlib.pyplot as plt
  
  with open('/home/tont_fe/Desktop/Extra_for_paper/Lifbase OH emission2.txt') as f:
      lines = f.readlines()
      x = [(line.split()[0]) for line in lines]
      item = [float(item) for item in x]
      y = [(line.split()[1]) for line in lines]
  </code></pre>
  <p>I receive the following error:</p>
  <p>ValueError: invalid literal for float(): 281,2</p>
  <p>example of data:
  281,228 0,01097</p>
  <p>281,2289    0,0096</p>
  <p>281,2297    0,00888</p>
  <p>281,2306    0,00883</p>
  <p>281,2315    0,00932</p>
  <p>281,2324    0,01008</p>
  <p>281,2333    0,01062</p>
  <p>281,2341    0,01058</p>
  <p>281,235 0,01013</p>
  <p>281,2359    0,00981</p>
  <p>281,2367    0,01013</p>
  <p>281,2376    0,01141</p>
  <p>281,2385    0,01377</p>