equal
deleted
inserted
replaced
541 True |
541 True |
542 >>> f and t |
542 >>> f and t |
543 False |
543 False |
544 |
544 |
545 The **while** loop |
545 The **while** loop |
546 ~~~~~~~~~~~~~~~~~~ |
546 ================== |
|
547 |
547 |
548 |
548 The Python **while** loop is similar to the C/C++ while loop. The syntax is as |
549 The Python **while** loop is similar to the C/C++ while loop. The syntax is as |
549 follows: |
550 follows: |
550 |
551 |
551 :: |
552 :: |
570 3 |
571 3 |
571 4 |
572 4 |
572 5 |
573 5 |
573 |
574 |
574 The **if** conditional |
575 The **if** conditional |
575 ~~~~~~~~~~~~~~~~~~~~~~ |
576 ====================== |
576 |
577 |
577 The Python **if** block provides the conditional execution of statements. |
578 The Python **if** block provides the conditional execution of statements. |
578 If the condition evaluates as true the block of statements defined under the if |
579 If the condition evaluates as true the block of statements defined under the if |
579 block are executed. |
580 block are executed. |
580 |
581 |
610 print n," is positive" |
611 print n," is positive" |
611 else: |
612 else: |
612 print n, " is 0" |
613 print n, " is 0" |
613 |
614 |
614 **raw_input()** |
615 **raw_input()** |
615 ~~~~~~~~~~~~~~~ |
616 =============== |
616 |
617 |
617 In the previous example we saw the call to the raw_input() subroutine. |
618 In the previous example we saw the call to the raw_input() subroutine. |
618 The **raw_input()** method is used to take user inputs through the console. |
619 The **raw_input()** method is used to take user inputs through the console. |
619 Unlike **input()** which assumes the data entered by the user as a standard python |
620 Unlike **input()** which assumes the data entered by the user as a standard python |
620 expression, **raw_input()** treats all the input data as raw data and converts |
621 expression, **raw_input()** treats all the input data as raw data and converts |
683 |
684 |
684 Observe here that the variable *pal* is a string and hence integer operations |
685 Observe here that the variable *pal* is a string and hence integer operations |
685 cannot be performed on it. Hence the exception is raised. |
686 cannot be performed on it. Hence the exception is raised. |
686 |
687 |
687 **int()** method |
688 **int()** method |
688 ~~~~~~~~~~~~~~~~ |
689 ================ |
689 |
690 |
690 Generally for computing purposes, the data used is not strings or raw data but |
691 Generally for computing purposes, the data used is not strings or raw data but |
691 on integers, floats and similar mathematical data structures. The data obtained |
692 on integers, floats and similar mathematical data structures. The data obtained |
692 from **raw_input()** is raw data in the form of strings. In order to obtain integers |
693 from **raw_input()** is raw data in the form of strings. In order to obtain integers |
693 from strings we use the method **int()**. |
694 from strings we use the method **int()**. |
713 'Guido Van Rossum' |
714 'Guido Van Rossum' |
714 >>> numvar = int(stringvar) |
715 >>> numvar = int(stringvar) |
715 |
716 |
716 |
717 |
717 Functions in Python: **def** |
718 Functions in Python: **def** |
718 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
719 ============================ |
719 |
720 |
720 *Functions* allow us to enclose a set of statements and call the function again |
721 *Functions* allow us to enclose a set of statements and call the function again |
721 and again instead of repeating the group of statements everytime. Functions also |
722 and again instead of repeating the group of statements everytime. Functions also |
722 allow us to isolate a piece of code from all the other code and provides the |
723 allow us to isolate a piece of code from all the other code and provides the |
723 convenience of not polluting the global variables. |
724 convenience of not polluting the global variables. |
807 |
808 |
808 >>> name = ['Mr.', 'Steve', 'Gosling'] |
809 >>> name = ['Mr.', 'Steve', 'Gosling'] |
809 >>> can_change(name) |
810 >>> can_change(name) |
810 >>> name |
811 >>> name |
811 ['Mr.', 'James', 'Gosling'] |
812 ['Mr.', 'James', 'Gosling'] |
812 |
|
813 If nothing is returned by the function explicitly, Python takes care to return |
813 If nothing is returned by the function explicitly, Python takes care to return |
814 None when the funnction is called. |
814 None when the funnction is called. |
815 |
815 |
816 Default Arguments |
816 Default Arguments |
817 ----------------- |
817 ----------------- |