How to add lables to the scatter plot?

[LK91]

It’s example of my code. Cluster - name of column where my labels are. Targets - name of my labels.

targets = ['0','1','2','3','4']
colors = ['red','blue','black','pink','green']
for target, color in zip(targets,colors):
    indicesToKeep = finalDf['Cluster'] == target
    ax.scatter(finalDf.loc[indicesToKeep, 'principal component 1']
               , finalDf.loc[indicesToKeep, 'principal component 2']
               , c = color
               , s = 50)
ax.legend(targets)
ax.grid()