A statement is a unit of code. Two types of statements are **print**and

**assignment.**In interactive mode interpreter execute the statement and display the result. In script mode includes sequence of statements.**Operators**are special symbols, that represent computations. The values the operator is applied to are called

**operands**.

Operators are + (Addition), - (Subtraction), *(Multiplication), / (Division), and ** (Exponentiation).

>>> a=44

>>> a/45

0

When both the operands are integers , then the result is round downs to zero. If either the operands is a floating point number , then the python perform the floating point division.

>>> a/45.0

0.97777777777777775

An

**Expression**is a combination of values, variables and operators.>>> x=56

>>> x+4

60

If more than one operator appears in an expression, the order of evaluation depends on the

**rules pf precedence**.- Parentheses have the highest precedence. eg. 2 * (3-1) is 4
- Exponentiation has the next higher precedence. eg. 2**1 + 1 is 3
- Multiplication and division have the same precedence. eg. 2*3-1 is 5
- Addition and subtraction have the next precedence. eg. 6+4/2 is 8. Operators with the same precedence are evaluated from left to right.

**Strings**are enclosed in single or double quotes. '+' operator used for concatenation.

Example:

>>> a='Hi'

>>> b='Alice'

>>> a+b # '+' is used for concatenation operation.

'HiAlice'

>>>

'*' operator is also work with string.

>>> a*3 # Disply the value of a in 3 times

'HiHiHi'

>>>

**Sample exercise**

*Assume that we execute the following assignment statements:*

width = 17height = 12.0delimiter = '.'

*For each of the following expressions, write the value of the expression*

*width/2**width/2.0**height/3**1 + 2 * 5**delimiter * 5*

*Use the Python interpreter to check your answers*

**Answer**

>>> width=17

>>> height=12.0

>>> delimiter = '.'

>>> width/2

8

>>> width/2.0

8.5

>>> height/3

4.0

>>> 1+2*5

11

>>> delimiter *5

'.....'

>>>

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