title: How to plot markers when a variable=1 or use 'axvspan' to highlight regions when a variable=1
body: <p>We have EURUSD data from 2 price feeds as shown below (100 row sample)</p>
  <h1>Data</h1>
  <pre class="lang-py prettyprint-override"><code>Date,sell_A,buy_A,sell_B,buy_B,buy_B_sell_A,mispricing_1,exploitable_1,buy_A_sell_B,mispricing_2,exploitable_2,Time
  2020-01-01 22:51:41.368,1.12144,1.1217,1.1216,1.12171,-26.999999999999247,0,0,-9.999999999998899,0,0,22:51:41.368000
  2020-01-01 22:51:41.978,1.12147,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:51:41.978000
  2020-01-01 22:51:43.189,1.12147,1.12171,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:51:43.189000
  2020-01-01 22:51:43.731,1.12147,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:51:43.731000
  2020-01-01 22:51:57.360,1.12137,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:51:57.360000
  2020-01-01 22:52:02.022,1.1213600000000001,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:52:02.022000
  2020-01-01 22:52:02.024,1.12151,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:52:02.024000
  2020-01-01 22:52:02.189,1.12148,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:52:02.189000
  2020-01-01 22:52:18.720,1.12142,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:52:18.720000
  2020-01-01 22:52:20.066,1.12148,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:52:20.066000
  2020-01-01 22:52:42.802,1.12148,1.1217700000000002,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:52:42.802000
  2020-01-01 22:52:42.972,1.12148,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:52:42.972000
  2020-01-01 22:52:45.320,1.1214899999999999,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:52:45.320000
  2020-01-01 22:52:45.489,1.12148,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:52:45.489000
  2020-01-01 22:53:01.489,1.1214600000000001,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:53:01.489000
  2020-01-01 22:53:20.940,1.12135,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:53:20.940000
  2020-01-01 22:53:22.823,1.12148,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:53:22.823000
  2020-01-01 22:53:22.826,1.1214600000000001,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:53:22.826000
  2020-01-01 22:53:26.589,1.12148,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:53:26.589000
  2020-01-01 22:53:27.929,1.1214600000000001,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:53:27.929000
  2020-01-01 22:53:28.895,1.1214899999999999,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:53:28.895000
  2020-01-01 22:53:38.038,1.12147,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:53:38.038000
  2020-01-01 22:53:39.027,1.12147,1.12171,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:53:39.027000
  2020-01-01 22:53:39.244,1.12147,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:53:39.244000
  2020-01-01 22:53:51.144,1.1213600000000001,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:53:51.144000
  2020-01-01 22:53:58.096,1.1213799999999998,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:53:58.096000
  2020-01-01 22:54:03.460,1.1214899999999999,1.12172,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:54:03.460000
  2020-01-01 22:54:05.330,1.1214899999999999,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:54:05.330000
  2020-01-01 22:54:21.404,1.1213799999999998,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:54:21.404000
  2020-01-01 22:54:22.852,1.12147,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:54:22.852000
  2020-01-01 22:54:23.080,1.12145,1.12168,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:54:23.080000
  2020-01-01 22:54:40.278,1.12135,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:54:40.278000
  2020-01-01 22:54:41.143,1.12143,1.12166,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:54:41.143000
  2020-01-01 22:54:42.898,1.12145,1.12168,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:54:42.898000
  2020-01-01 22:54:47.548,1.12147,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:54:47.548000
  2020-01-01 22:55:05.642,1.12135,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:55:05.642000
  2020-01-01 22:55:30.874,1.12133,1.12176,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:55:30.874000
  2020-01-01 22:55:40.157,1.12132,1.12178,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:55:40.157000
  2020-01-01 22:55:41.599,1.12133,1.12178,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:55:41.599000
  2020-01-01 22:55:42.564,1.1214600000000001,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:55:42.564000
  2020-01-01 22:56:12.622,1.12135,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:56:12.622000
  2020-01-01 22:56:12.945,1.12144,1.12168,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:56:12.945000
  2020-01-01 22:56:28.780,1.12135,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:56:28.780000
  2020-01-01 22:57:07.971,1.12145,1.1216899999999999,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:57:07.971000
  2020-01-01 22:57:27.648,1.12135,1.12174,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:57:27.648000
  2020-01-01 22:57:29.527,1.12133,1.12174,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:57:29.527000
  2020-01-01 22:57:30.644,1.12134,1.12172,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:57:30.644000
  2020-01-01 22:57:30.646,1.12143,1.1216700000000002,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:57:30.646000
  2020-01-01 22:57:47.624,1.12135,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:57:47.624000
  2020-01-01 22:58:25.640,1.12144,1.12168,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:58:25.640000
  2020-01-01 22:58:29.615,1.12143,1.12166,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:58:29.615000
  2020-01-01 22:58:51.560,1.12135,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:58:51.560000
  2020-01-01 22:59:24.612,1.12142,1.12166,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:59:24.612000
  2020-01-01 22:59:40.937,1.12135,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:59:40.937000
  2020-01-01 22:59:50.980,1.12135,1.1216899999999999,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:59:50.980000
  2020-01-01 22:59:52.092,1.12131,1.12166,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:59:52.092000
  2020-01-01 22:59:52.525,1.12135,1.1216899999999999,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:59:52.525000
  2020-01-01 22:59:57.627,1.12135,1.12168,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:59:57.627000
  2020-01-01 22:59:58.951,1.12135,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,22:59:58.951000
  2020-01-01 23:00:00.366,1.12141,1.12164,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:00:00.366000
  2020-01-01 23:00:03.068,1.12142,1.1216700000000002,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:00:03.068000
  2020-01-01 23:00:04.847,1.1214600000000001,1.12162,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:00:04.847000
  2020-01-01 23:00:06.084,1.1214600000000001,1.12164,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:00:06.084000
  2020-01-01 23:00:19.153,1.1213899999999999,1.12166,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:00:19.153000
  2020-01-01 23:00:20.209,1.12147,1.12165,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:00:20.209000
  2020-01-01 23:00:24.538,1.1215,1.12166,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:00:24.538000
  2020-01-01 23:00:25.054,1.12152,1.1216899999999999,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:00:25.054000
  2020-01-01 23:00:25.236,1.1214899999999999,1.12168,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:00:25.236000
  2020-01-01 23:00:25.738,1.1214899999999999,1.1216899999999999,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:00:25.738000
  2020-01-01 23:00:26.257,1.1214899999999999,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:00:26.257000
  2020-01-01 23:00:26.259,1.1214899999999999,1.1216899999999999,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:00:26.259000
  2020-01-01 23:00:27.074,1.12154,1.1216899999999999,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:00:27.074000
  2020-01-01 23:00:28.086,1.12154,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:00:28.086000
  2020-01-01 23:00:29.206,1.1215600000000001,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:00:29.206000
  2020-01-01 23:00:29.376,1.1215899999999999,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:00:29.376000
  2020-01-01 23:00:29.429,1.1215899999999999,1.12172,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:00:29.429000
  2020-01-01 23:00:29.723,1.1215899999999999,1.12174,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:00:29.723000
  2020-01-01 23:00:32.376,1.1215899999999999,1.12175,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:00:32.376000
  2020-01-01 23:00:32.823,1.1216,1.12175,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:00:32.823000
  2020-01-01 23:00:35.094,1.1216,1.12174,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:00:35.094000
  2020-01-01 23:00:35.313,1.12161,1.12175,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:00:35.313000
  2020-01-01 23:00:35.316,1.12162,1.12175,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:00:35.316000
  2020-01-01 23:00:35.317,1.12162,1.12176,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:00:35.317000
  2020-01-01 23:00:36.054,1.12161,1.12172,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:00:36.054000
  2020-01-01 23:00:37.001,1.12162,1.12174,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:00:37.001000
  2020-01-01 23:00:37.055,1.12161,1.12172,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:00:37.055000
  2020-01-01 23:00:40.232,1.12161,1.1217,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:00:40.232000
  2020-01-01 23:00:45.904,1.12161,1.12171,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:00:45.904000
  2020-01-01 23:00:48.687,1.12163,1.12171,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:00:48.687000
  2020-01-01 23:00:48.864,1.12164,1.12171,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:00:48.864000
  2020-01-01 23:00:49.186,1.12164,1.12173,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:00:49.186000
  2020-01-01 23:00:50.347,1.12164,1.12172,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:00:50.347000
  2020-01-01 23:00:58.893,1.12166,1.12172,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:00:58.893000
  2020-01-01 23:00:59.591,1.12166,1.12173,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:00:59.591000
  2020-01-01 23:01:01.089,1.12166,1.12172,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:01:01.089000
  2020-01-01 23:01:04.094,1.12168,1.12178,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:01:04.094000
  2020-01-01 23:01:04.097,1.12171,1.1218,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:01:04.097000
  2020-01-01 23:01:04.100,1.12173,1.12188,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:01:04.100000
  2020-01-01 23:01:04.104,1.1217700000000002,1.122,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:01:04.104000
  2020-01-01 23:01:04.158,1.1217700000000002,1.12204,1.1216,1.12171,-24.000000000001798,0,0,-9.999999999998899,0,0,23:01:04.158000
  </code></pre>
  <p>We have plotted variables 'buy_A' and 'sell_B' on a graph, shown below using this code;</p>
  <h1>Code to plot EURUSD chart</h1>
  <pre class="lang-py prettyprint-override"><code>plt.figure(figsize=[20,7])
  plt.plot(data.Date, data.buy_A, 'r', label='Buy_A')
  plt.plot(df.Date, df.sell_B, 'b', label='Sell_B')
  plt.legend(loc=&quot;upper left&quot;)
  plt.title(&quot;Buy A Sell B Graph&quot;)
  plt.xlabel('Date')
  plt.ylabel('Price')
  plt.show()
  </code></pre>
  <p><a href="https://i.stack.imgur.com/T5wn7.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/T5wn7.png" alt="enter image description here" /></a></p>
  <p>We now want to plot markers on this chart when 'exploitable_1==1'. 'exploitable_1' = 1 when the difference between 'buy_A' and 'sell_B' &gt;6.</p>
  <p>We looked into using the axvspan function to highlight multiple vertical columns for all the areas where 'exploitable_1==1' and also want to use markers but not sure how to do either.</p>