write me a program in python that uses matplotlib to ask the user for some data, then displays it in a bar graph.
Sure! Here's an example of how you can use MatPlotLib and Python to create a simple bar chart:

```python 
# Import necessary modules
from numpy import array
import pandas as pd
import matplotlib.pyplot as plt 

# Load data from csv file into DataFrame object
df = pd.read_csv("datafile.csv")

# Create empty figure with axes
fig, axs = plt.subplots(ncols=2)

# Set position of first column (index) of DataFrame on x-axis
axs[0].set_position([0., 0.5])  # set position at bottom left corner of axis

# Plot bars representing values from second column of DataFrame
for i in range(len(df)):
    y_value = df.iloc[:, 1][i]
    axs[1].bar([], y_value, width=20, color="blue", edgecolor="#d6a48e")

    # Update legend entry if applicable
    if len(list(df.columns)) > 2:
        plt.legend()

# Show plot
plt.show()
```

This script imports the necessary packages and reads data from a CSV file called "datafile.csv". The code creates two subplots using MatPlotLib, sets their positions, plots bars for each value in the second column of the DataFrame, and updates the legends when there are more than two columns in the DataFrame. Finally, the plot is shown by calling `plt.show()` function.