How to make a legend with matplotlib plotting a map? - pandas

Question

I have the following plot:
Inside this map you see some random coloured areas with numbers in it. The numbers are 12,25,34,38 and 43. Now I want to add a legend in the above left corner with the numbers followed by the name of the area. Something like this:
The annotation (The numbers in the areas) are added though a for loop using the following command ax.annotate(number, xy = ...). Can somebody tell me how to add a legend with all the numbers and text in some sort of a legend similar to the image above?
The numbers and names are both inside a pandas dataframe.
fig, ax = plt.subplots(1,1)
fig.set_size_inches(8,8) # setting the size
# Plot values - with grey layout
grey_plot = schap.plot(ax = ax, color = 'grey')
schap.plot(ax = grey_plot, column= col1, cmap= 'YlGnBu', legend = True)
# Add annotation for every waterschap with a deelstroomgebied
bbox_props = dict(boxstyle="round", fc="w", ec="gray", alpha=0.9,lw=0.4)
for idx, row in schap.iterrows():
if not np.isnan(row[col1]):
string = str(idx)
ax.annotate(string, xy=row['coords'], color='black',
horizontalalignment='center', bbox=bbox_props, fontsize=7)
'schap'
is the pandas dataframe with all needed data. schap['text'] contains all names. In a for loop this would be row['text'].

Answer 1

After the loop you can simply add text, for example:
ax.text(0.01, 0.99, legend,
horizontalalignment='left',
verticalalignment='top',
transform=ax.transAxes,
fontsize=8)
where legend can be updated inside your loop (desc is column with description):
legend = ''
#...
#inside your loop
legend = legend + f"{idx} {row['text'])}\n"
EDIT:
Example with different data (and aligment of legend):
import geopandas
import matplotlib.pyplot as plt
fig, ax = plt.subplots(1,1)
fig.set_size_inches(20,8)
world.plot(column='gdp_md_est', ax=ax, legend=True)
world['coords'] = world['geometry'].apply(lambda x: x.representative_point().coords[:][0])
bbox_props = dict(boxstyle="round", fc="w", ec="gray", alpha=0.9,lw=0.4)
legend = ''
for idx, row in world.iterrows():
if row['pop_est'] > 100_000_000:
plt.annotate(str(idx), xy=row['coords'], color='black',
horizontalalignment='center', bbox=bbox_props, fontsize=7)
legend = legend + f"{idx} {row['name']}\n"
ax.text(0.01, 0.5, legend,
horizontalalignment='left',
verticalalignment='center',
transform=ax.transAxes,
fontsize=8);