Binned data with pandas value_count() sends Error: Endstream has been closed

If you ran this code in Grasshopper python, you would get EndOfStreamException error.

import pandas as pd
import numpy as np
import matplotlib.pyplot as plt

idx = pd.Index([21, 13, 33,36, 40,44, 50, 18, 50, 14])
idx_bins = [10, 20, 30, 40, 51]
binned_idx = pd.cut(idx,idx_bins,right = False)

prob = binned_idx.value_counts().plot(kind='bar')

I figured the issue is with this line:

prob = binned_idx.value_counts().plot(kind='bar')

Once binned_idx is replaced with idx, the issue is resolved.
But that would not give us the graph of binned_idx,