1. D ATA T YPE

2. NUMBERS A number is an immutable type – means that changing or updating its value result in a newly allocated object. There are several types of numeric types – Integer Long integer Boolean Double –precision floating point real numbers Decimal floating point numbers Complex numbers

3. I NTEGERS There are several types of integers Boolean type – 2 possible values, True and False Actually an integer and behave like integer values 0 and 1 if used in numeric context. Standard Integers Python standard integers are the universal numeric type. Most machines (32-bit) running Python will provide a range of -2 31 to 2 31 -1 ( -2,147,483,648 to 2,147,483,647) Example of integer : 0101, 84, -234,Ox80 etc Integers are normally represented in base 10 decimal format. It can also be represented in base 8 (octal, “0” prefix)or base 16 (hexadecimal, “0x”/”OX” prefixes)

4. L ONG INTEGERS Longs are a superset of integers It is useful when your application requires integers that exceed the range of plain /standard integers. Use of longs is denoted by the letter ‘L’, uppercase (L) or lowercase (l), appended to the integer’s numeric values. Values can be expressed in decimal, octal, or hexadecimal. Examples : 16384L,-Ox4E8L,- 5432101234L,2997924581l

5. D OUBLE PRECISION FLOATING POINT NUMBERS Floating point values are denoted by a decimal point (.) in the appropriate place and an optional “e” suffix representing scientific notation. Can use either lowercase (e) or uppercase (E). Positive (+)/negative (-) signs between the “e” and the exponent indicate the sign of the exponent. No sign indicate positive exponent. Examples : 0.0, -5.55557119, -1.609E-19,3.67 etc

6. C OMPLEX NUMBERS Combining a real number with an imaginary number Example: 64.375 +1j, 0.23-8.55j,9.80665-8.31441J

7. O PERATORS - NUMERIC TYPE ( ARITHMETIC ) Division Classic division Using integer operands, classic division truncates the fraction, returning an integer (floor division). Using a pair of floating point operands, it returns the actual floating-point quotient (true division). Example : >>> 1/2 #perform integer result (floor) 0 >>> 1.0/2.0 #returns actual quotient 0.5

8. CONTINUE True division the division always returns the actual quotient regardless of the type of the operands For now, to take advantage of true division, need to give the from_future_import division directive. Once that happens, the division operator (/) performs only true division. >>> from_future_import division >>> >>>1/2 0.5 >>>1.0/2.0 0.5

9. CONTINUE Floor division (//)- always truncates the fraction and rounds it to the next smallest whole number toward the left on the number line, regardless of the operands’ numeric types. Examples: >>> 1 // 2 0 >>>1.0 // 2.0 0.0 >>>-1 // 2

10. M ODULUS Integer modulus is straightforward integer division remainder. Exponentiation Has a peculiar/strange precedence rule in its relationship with the unary operators. It binds more tightly than unary operators to its left, less tightly than unary operators to its right. example: >>> 3 ** 2 9

11. CONTINUE >>> -3 ** 2 # perform 3 to the power of two before applies the unary negation -9 >>> (-3) ** 2 9

12. E XAMPLES OF NUMERIC OPERATORS >>> -442 -77 -519 >>> 4**3 64 >>> 4.2 ** 3.2 98.7183139527 >>> 8/3 2 >>> 8.0/3.0 2.66666666667 >>> 8 % 3 2

13. CONTINUE >>> (60. -32.) * (5./9.) 15.5555555556 >>> 14 * 0x04 56 >>> 0170/4 30 >>> 45L * 22L 990L

14. N UMERIC TYPE FUNCTIONS Functionoperation bool (obj)Returns the boolean value of obj. int (obj,base =10)Returns integer representing of string or number obj. long (obj, base =10)Returns long representation of string or number obj. float (obj)Returns floating point representation of string or number obj complex (str)Returns complex number representation of str, or builds one given real

15. EXAMPLES >>> int (4.2555) 4 >>> long (42) 42L >>> float(4) 4.0 >>>complex(4) (4+0j)

16. OPERATIONAL Python has five operational built-in function for numeric types: abs() – returns the absolute value of the given argument. If the argument is a complex number, then math.sqrt(num.real 2 +num.imag 2 ) is returned. coerce ( ) – returns a tuple containing the converted pair of numbers. divmod ( ) –combines division and modulus operations into a single function. The values returned are the same as those given for the classic division and modulus operator for integer type. As for float, the quotient returned math.floor(num1/num2). As for complex numbers, the quotient is math.floor((num1/num2).real)

17. CONTINUE pow ( ) – pow () and ** perform exponentiation, one is operator (**), and the other is build-in function. round ( ) – has a syntax of round(flt,ndig=0) rounds a floating point number to the nearest integral number and returns that result still in a float. When the optional ndig is given, round () will round the argument to the specific number of decimal places.

18. E XAMPLE abs () >>> abs(-1) 1 >>> abs (10.) 10.0 >>> abs (0.23-0.78) 0.55 coerce () >>> coerce(1,2) (1,2) >>>coerce (1,134L) (1L,134L)

19. C ONTINUE WITH EXAMPLES >>>divmod(10,3) (3,1) >>> divmod (3,10) (0,3) >>> pow(2,5) 32 >>> round (3) 3.0 >>> round(3.49999,1) 3.5 >>> bool(1) True >>> bool(True) True >>> bool(‘1’) True