Number data types store numeric values. They are immutable data types, which means that changing the value of a number data type results in a newly allocated object.
Number objects are created when you assign a value to them. For example:
var1 = 1 var2 = 10
You can also delete the reference to a number object by using the del statement. The syntax of the del statement is:
You can delete a single object or multiple objects by using the del statement. For example:
del var del var_a, var_b
Python supports four different numerical types:
int (signed integers): often called just integers or ints, are positive or negative whole numbers with no decimal point.
long (long integers ): or longs, are integers of unlimited size, written like integers and followed by an uppercase or lowercase L.
float (floating point real values) : or floats, represent real numbers and are written with a decimal point dividing the integer and fractional parts. Floats may also be in scientific notation, with E or e indicating the power of 10 (2.5e2 = 2.5 x 102 = 250).
complex (complex numbers) : are of the form a + bJ, where a and b are floats and J (or j) represents the square root of -1 (which is an imaginary number). a is the real part of the number, and b is the imaginary part. Complex numbers are not used much in Python programming.
Here are some examples of numbers:
Python allows you to use a lowercase L with long, but it is recommended that you use only an uppercase L to avoid confusion with the number 1. Python displays long integers with an uppercase L.
A complex number consists of an ordered pair of real floatingpoint numbers denoted by a + bj, where a is the real part and b is the imaginary part of the complex number.
Number Type Conversion:
Python converts numbers internally in an expression containing mixed types to a common type for evaluation. But sometimes, you'll need to coerce a number explicitly from one type to another to satisfy the requirements of an operator or function parameter.
Type int(x)to convert x to a plain integer.
Type long(x) to convert x to a long integer.
Type float(x) to convert x to a floating-point number.
Type complex(x) to convert x to a complex number with real part x and imaginary part zero.
Type complex(x, y) to convert x and y to a complex number with real part x and imaginary part y. x and y are numeric expressions
Python includes following functions that perform mathematical calculations.
|Function||Returns ( description )|
|abs(x)||The absolute value of x: the (positive) distance between x and zero.|
|ceil(x)||The ceiling of x: the smallest integer not less than x|
|cmp(x, y)||-1 if x < y, 0 if x == y, or 1 if x > y|
|exp(x)||The exponential of x: ex|
|fabs(x)||The absolute value of x.|
|floor(x)||The floor of x: the largest integer not greater than x|
|log(x)||The natural logarithm of x, for x> 0|
|log10(x)||The base-10 logarithm of x for x> 0 .|
|max(x1, x2,...)||The largest of its arguments: the value closest to positive infinity|
|min(x1, x2,...)||The smallest of its arguments: the value closest to negative infinity|
|modf(x)||The fractional and integer parts of x in a two-item tuple. Both parts have the same sign as x. The integer part is returned as a float.|
|pow(x, y)||The value of x**y.|
|round(x [,n])||x rounded to n digits from the decimal point. Python rounds away from zero as a tie-breaker: round(0.5) is 1.0 and round(-0.5) is -1.0.|
|sqrt(x)||The square root of x for x > 0|
Random Number Functions:
Random numbers are used for games, simulations, testing, security, and privacy applications. Python includes following functions that are commonly used.
|choice(seq)||A random item from a list, tuple, or string.|
|randrange ([start,] stop [,step])||A randomly selected element from range(start, stop, step)|
|random()||A random float r, such that 0 is less than or equal to r and r is less than 1|
|seed([x])||Sets the integer starting value used in generating random numbers. Call this function before calling any other random module function. Returns None.|
|shuffle(lst)||Randomizes the items of a list in place. Returns None.|
|uniform(x, y)||A random float r, such that x is less than or equal to r and r is less than y|
Python includes following functions that perform trigonometric calculations.
|acos(x)||Return the arc cosine of x, in radians.|
|asin(x)||Return the arc sine of x, in radians.|
|atan(x)||Return the arc tangent of x, in radians.|
|atan2(y, x)||Return atan(y / x), in radians.|
|cos(x)||Return the cosine of x radians.|
|hypot(x, y)||Return the Euclidean norm, sqrt(x*x + y*y).|
|sin(x)||Return the sine of x radians.|
|tan(x)||Return the tangent of x radians.|
|degrees(x)||Converts angle x from radians to degrees.|
|radians(x)||Converts angle x from degrees to radians.|
The module also defines two mathematical constants:
|pi||The mathematical constant pi.|
|e||The mathematical constant e.|