Python Notes – Part I

Build-in types


Numeric Types Precision  Internally Literal Creation
integers Have unlimited precision i = 5
floating point System dependent precision values check – sys.float_info implemented using double in C f = 5.5
complex numbers real + img implemented as floating point number  c = 2j


  • c = 2j  Yields an imaginary number (a complex number with a zero real part) add to an integer or float to get a complex number with real and imaginary parts.


Operations on Numeric Types


Operation Result
x + y sum of x and y
x - y difference of x and y
x * y product of x and y
x / y quotient of x and y
x // y floored quotient of x and y
x % y remainder of x / y
-x x negated
+x x unchanged
abs(x) absolute value or magnitude of x
int(x) x converted to integer
float(x) x converted to floating point
complex(re, im) a complex number with real part re, imaginary part im. im defaults to zero.
c.conjugate() conjugate of the complex number c
divmod(x, y) the pair (x // y, x % y)
pow(x, y) x to the power y
x ** y x to the power y

Strings *

  • Methods that use dot notation only work with strings.
  • On the other hand, len() and str() can work on other data types