widden the pandas example

Author: 12rambau

docs/examples/pydata.md

@@ -25,8 +25,8 @@ import numpy as np
 import pandas as pd
 
 rng = np.random.default_rng()
-data = rng.standard_normal((100, 3))
-df = pd.DataFrame(data, columns=['a', 'b', 'c'])
+data = rng.standard_normal((100, 26))
+df = pd.DataFrame(data, columns=list(string.ascii_lowercase))
 df
 ```