Typing a number at the Python shell prompt simply echoes the number back to you:
>>> 5 5 >>> 5. 5.0 >>> 0.10 0.1 >>> 0.0001 0.0001 >>> 0.0000999 9.99e-05
Note that the Python interpreter displays numbers in a standard way. For example, numbers smaller in magnitude than 0.0001 are displayed in scientific notation.
A number of one type can be created from a number of another type with the relevant constructor:
>>> float(5) 5.0 >>> int(5.2) 5 >>> int(5.9) 5
Note that a floating point number is rounded down in casting it into an integer.
Constructing a complex object from a float generates a complex number with the imaginary part equal to zero:
>>> complex(3.) (3+0j)
To generate a pure imaginary number, you have to explicitly pass two numbers to complex with the first, real part, equal to zero:
>>> complex(0., 3.) 3j