In [5]:
L = 5
d = 0.02

nu = 1e-6
rho = 1000

u = 0.001

Re = u*d/nu

print "Re = %f" % Re

f = 64.0/Re

dp = 0.5*f*rho*u*u*L/d

print "dp = %f Pa" % dp


Re = 20.000000
dp = 0.400000 Pa