import psycopg2 as pg
conn = pg.connect(database="magazine_renewal",user="", password="")
cur = conn.cursor()
cur.execute("SELECT order_amt FROM customer_orders WHERE order_amt <> 0
AND order_amt IS NOT NULL LIMIT(10000)")
records = cur.fetchall()
cur.close()
conn.close()
records[:10]

[(Decimal('69.95'),),
(Decimal('79.95'),),
(Decimal('199.95'),),
(Decimal('79.95'),),
(Decimal('69.95'),)]

from scipy.stats import norm

import matplotlib.pyplot as plt
plt.plot(records, norm.pdf(records))

TypeError                                 Traceback (most recent call last)
<ipython-input-92-8143f3270f83> in <module>()
  3
  4 #x = np.arange(-3, 3, 0.001)
----> 5 plt.plot(records, norm.pdf(records))

/Users/john/Library/Enthought/Canopy/edm/envs/User/lib/python3.5/site-
packages/scipy/stats/_distn_infrastructure.py in pdf(self, x, *args,
**kwds)
   1655         cond = cond0 & cond1
   1656         output = zeros(shape(cond), dtyp)
-> 1657         putmask(output, (1-cond0)+np.isnan(x), self.badvalue)
   1658         if np.any(cond):
   1659             goodargs = argsreduce(cond, *((x,)+args+(scale,)))

TypeError: ufunc 'isnan' not supported for the input types, and the
inputs could not be safely coerced to any supported types according to
the casting rule ''safe''