Python supports four different numeric types:
- Integer (Int) - commonly referred to as Integer or Integer, is a positive or negative integer without a decimal point.
- long integers - Integers of infinite size, with an upper or lower case L at the end of the integer.
- Floating point (floating point real values) - Floating point consists of integer part and fractional part. Floating point can also be represented in scientific notation (2.5e2 = 2.5 x 10 2 = 250)
- Complex numbers - complex numbers consist of a real part and an imaginary part, which can be represented by a + bj, or complex(a,b). The real part a and the imaginary part b of the complex number are both floating-point types.
- A lowercase "L" can also be used for long integers, but it is recommended that you use an uppercase "L" to avoid confusion with the number "1". Python uses "L" to display long integers.
- Python also supports complex numbers. A complex number consists of a real part and an imaginary part. It can be represented by a + bj, or complex(a, b). The real part a and the imaginary part b of the complex number are both floating-point types.
Python Number type conversion
int (x [,base ]) #Convert x to an integer long (x [,base ]) #Convert x to a long integer float (x ) #Convert x to a float complex(real [,imag ] ) #creates a complex number str(x) #converts object x to string repr(x) #converts object x to expression string eval(str) #used to evaluate valid Python expressions in strings, and Returns an object tuple(s) #converts the sequence s to a tuple list(s) #converts the sequence s to a list chr(x) #converts an integer to a character unichr(x) #converts an integer to Unicode character ord(x) # Convert a character to its integer value hex(x) #Convert an integer to a hexadecimal string oct(x) #Convert an integer to an octal string
Python math module, cmath module
The functions commonly used in mathematical operations in Python are basically in the math module and cmath module .
The Python math module provides many functions for mathematical operations on floating-point numbers.
The Python cmath module contains some functions for complex arithmetic.
The functions of the cmath module are basically the same as those of the math module. The difference is that the cmath module operates on complex numbers, while the math module operates on mathematical operations.
To use the math or cmath function you must first import:
import math
Check out math to see what's in the package:
>>> import math >>> dir(math)
>>> 省略....
Python math functions
abs(x) #return the absolute value of the number, such as abs(-10) return 10 ceil(x) #return the integer of the number, such as math.ceil( 4.1) return 5 cmp(x, y) #if x < y returns -1, if x == y returns 0, if x > y returns 1 exp(x) # returns e to the power of x (ex), such as math.exp( 1) returns 2.718281828459045 fabs(x) # returns a number The absolute value of , such as math.fabs( -10) returns 10.0 floor(x) #Returns the rounded integer of the number, such as math.floor( 4.9) returns 4 log(x) #Such as math.log(math.e) returns 1. 0, math.log(100,10) returns 2.0 log10(x) #Returns the logarithm of x in base 10, such as math.log10( 100) returns 2.0 max(x1, x2,...) # Returns the maximum value for the given argument, which can be a sequence. min(x1, x2,...) #Return the minimum value of the given parameter, the parameter can be a sequence. modf(x) #Return the integer part and the fractional part of x, the numerical sign of the two parts is the same as x, and the integer part is represented by a floating point type. pow(x, y) #x ** y The value after the operation. round(x [,n]) #Returns the rounded value of the floating-point number x, if n is given, it represents the number of digits rounded to the decimal point. sqrt(x) #returns the square root of the number x
Python random number function
Random numbers can be used in mathematics, games, security and other fields, and are often embedded in algorithms to improve algorithm efficiency and improve program security.
Python includes the following commonly used random number functions:
choice(seq) #Randomly pick an element from the elements of the sequence, such as random.choice(range(10 )), randomly pick an integer from 0 to 9. randrange ([start,] stop [,step]) #Get a random number from the set that increases by the specified cardinality within the specified range, the default value of the cardinality is 1 random() #Randomly generate the next real number, which is in [ 0 ,1 ) range. seed([x]) #Change the seed seed of the random number generator. If you don't understand how it works, you don't have to set the seed, Python will choose the seed for you. shuffle(lst) #Randomly sort all elements of the sequence uniform(x, y) #Randomly generate the next real number, which is in the range [x,y].
Python trigonometry
Python includes the following trigonometric functions:
acos(x) #Returns the arc cosine of x in radians. asin(x) #Returns the arcsine of x in radians. atan(x) #Returns the arc tangent of x in radians. atan2(y, x) #Returns the arctangent of the given X and Y coordinate values. cos(x) #Returns the cosine of x in radians. hypot(x, y) #Return Euclidean norm sqrt(x *x + y* y). sin(x) # Returns the sine of x in radians. tan(x) #Returns the tangent of x in radians. degrees(x) #Convert radians to degrees, such as degrees(math.pi /2), return 90.0 radians(x) #Convert angles to radians
Python math constants
pi #mathematical constant pi (pi, generally expressed as π)
e #mathematical constant e, e is the natural constant (natural constant).