Python can be used as a calculator, directly on the command line.



In [11]:

    
2 + 3

Numbers can be written in binary, decimal, octal and hexadecimal. Anything after a "#" on a line is a comment.



In [19]:

    
print 0b10 # binary!
print 010 # octal
print 10 # decimal
print 0x10 # hexadecimal

All arithmetic operators, and paranthesis works, as you'd expect:



In [12]:

    
(2+3)*12/2









    Out[12]:





30

Python's integer datatype is an "int". This is internally implemented using the C language datatype "long".



In [4]:

    
z = (2+3)*12/2
type(z)









    Out[4]:





int

Bitwise operations are supported too.



In [16]:

    
0xf2 & 0x0f









    Out[16]:





2

However, arbitrary precision arithmetic is supported as well - without limits! Can you count count the number of digits in the result ?



In [9]:

    
x = 12
y = 80
x ** y # i.e 12 raised to the power 80









    Out[9]:





216022846201030691200209793924791130326656901023785450335762680219510291602196530200576L

But you don't need to... why count when you can have python do it for you ? The inbuilt str() function converts anything to its string representation



In [10]:

    
z = x**y
len(str(z))









    Out[10]:





87

Floating point works too... and is internally represented using C datatype double.



In [13]:

    
1.0 * 2.0









    Out[13]:





2.0

The scientific notation works for floating point numbers.



In [21]:

    
2.2456e-5









    Out[21]:





2.2456e-05

Note: python converts to floating point only when a floating point value is used. So, 1/2 returns zero, rather than 0.5



In [15]:

    
print 1/2
print 1/2.0
print 1./2
print 1./2.