title: How do I apply a line between two points in geopanda e.g. between 2 cities
body: <p>I am trying to plot a green line between the 2 cities on my map in geopandas
  The result should show the 2 cities with the red point and the name of the cities as well plus a green line between the two cities</p>
  <p>I hope you can help me!
  Thanks in ahead!</p>
  <p>I tried it a few times but I dont get the key for plotting a line</p>
  <pre><code>import geopandas as gpd
  import pandas as pd
  import numpy as np
  import matplotlib.pyplot as plt
  
  
  ###################### The Map of Germany is plotted here
  
  plt.style.use('seaborn')
  plz_shape_df = gpd.read_file(r'C:\Users\XXXXX\geopanda\plz-gebiete.shp', dtype={'plz': str})
  plz_shape_df.head()
  plt.rcParams['figure.figsize'] = [16, 11]
  fig, ax = plt.subplots()
  plz_shape_df.plot(ax=ax, color='orange', alpha=0.8)
   
  ax.set(
         title='Germany', 
         aspect=1.3, 
         facecolor='lightblue');
  
  ################ The dict: new_dict3 with the 2 cities gets plotted
  
  new_dict3 = {
      'Stuttgart': (9.181332, 48.777128),
      'Munich': (11.576124, 48.137154),
      }
  
  for c in new_dict3.keys():
     ax.text(
         x=new_dict3[c][0],
         y=float(new_dict3[c][1]) + 0.1,
         s=c,
         fontsize = 12,
         ha = &quot;center&quot;,
         )
          
     ax.plot(
          new_dict3[c][0],
          new_dict3[c][1],
          marker = &quot;o&quot;,
          c = &quot;red&quot;,
          alpha = 2.0
          )
  
  ############### Now I want to plot a green line between the 2 cities of the new_dict3
  
     ax.plot(
          x= new_dict3[c][0],
          y= float(new_dict3[c][1]) + 0.1,
          linestyle = &quot;--&quot;,
          c = &quot;green&quot;,
          marker=&quot;&quot;,
          )
  
      #this doesn't work
      
  </code></pre>
  <p>[<img src="https://i.stack.imgur.com/gL6GW.png" alt="the result of plotting the map before trying to plot the line" /></p>