Operator (operator)
operator can computes various operations or a value or values
such as +, -, *, / operators belonging
operator classification:
1. arithmetic operators (addition, subtraction)
+ addition operator (if it is an addition operation between two strings, the string operation is performed fight)
- subtraction operator
* multiplication operator
/ division operator
// divisible only saves integer bits in the art
** exponentiation , find the value of a power of a few
remainders modulo%, average of two numbers divided by
2. the assignment operator
variable assignment operator can be given the value to the right of the equal sign on the left side of the equal sign
+ = a + = 5 A + =. 5 corresponds to the A
- A = - =. 5 corresponds to A = A -. 5
* = * =. 5 corresponds to A = A *. 5 A
** A ** = = =. 5 corresponds to the A **. 5 A
/ = a / = 5 corresponds to A = A /. 5
// // A = =. 5 corresponds to a = a // 5
3. Comparison operators (relational operators)
relational operators are used to compare the relationship between the two values, always returns a Boolean value
if the relationship was established, the return True, otherwise return False
>> - <<= == =!
can be greater than two strings in python (equal) or less than (equal to) is performed
when the string comparison, the comparison is actually encoded Unicode strings (UTF-8)
If you do not want to compare two Unicode encoding strings, it needs to be converted to digital and then in the comparison
4. Logical Operators
Logical Operators mainly used for some logic determines
not logical negation
not may be made to the right of the symbol values of the non-operation
for Boolean NOT operation will be negated operation
for non-Boolean NOT operation will first convert it to a Boolean value, and then negated
and logic
and can operate on both sides of the symbol values
and the calculation is to find the False, False if the first value, the second value is not watching
True and print ( "I guess you do not come out!") # The first is True, we will look at the second value, all outputs
False and print ( "I guess you do not come out!") # The first is False, will not see the second value, not all outputs
or logic or
or can operate on both sides of the symbolic value
or value as long as the two operations there True, returns True
or operation is to find True, if the first value is True, not to see a second value
False or print ( "I guess you do not come out!") # the first value is not True, the will output
True or print ( "I guess you do not come out!") # The first value is True, it will not output
the operation or non-Boolean values
when we or the operation of the non-Boolean value, python as it will Boolean value calculation, the original value of the final return
The conditional operator (ternary operator)
Syntax: 1 if the statement of the conditional expression 2 else statement
execution process:
conditional operator, when executed, will first conditional expressions are evaluated determination
If the determination result is True, the execution 1 statement, and returns the execution result
if the determination result is False, the statement 2 is executed, and returns the execution result of
operator precedence
and numerals as in the python operation has priority, such as first multiplication and division, after subtraction