# Euler's number e, the base of natural logs
# e is the sum of this infinite series:
# e = 1/0! + 1/1! + 1/2! + 1/3! + 1/4! + ...
# or simplified ...
# e = 2 + 1/2! + 1/3! + 1/4! + ...
# to get higher floating point precision use the module decimal
# tested with Python25     vegaseat     08jan2008
 
import decimal as dc
 
# set the precision
dc.getcontext().prec = 101
 
factorial = 1
euler = 2
for x in range(2, 150):
    factorial *= x
    euler += dc.Decimal(str(1.0))/dc.Decimal(str(factorial))
 
print "Eulers number calculated and 100 digit reference below:"
 
print euler
 
# e from http://www.gutenberg.org/etext/127  (up to 1 million places)
e = "2.7182818284590452353602874713526624977572470936999595749669676277\
240766303535475945713821785251664274"
 
print e
 
"""
my output --->
Eulers number calculated and 100 digit reference below:
2.7182818284590452353602874713526624977572470936999595749669676277240766303535475945713821785251664274
2.7182818284590452353602874713526624977572470936999595749669676277240766303535475945713821785251664274
"""