Archive:Think Python/Classes and functions - Revision history

wikademia>Wikademia: moved Think Python/Classes and functions to Archive:Think Python/Classes and functions

2009-05-18T20:09:10Z

moved Think Python/Classes and functions to Archive:Think Python/Classes and functions

← Older revision	Revision as of 20:09, 18 May 2009
(No difference)

wikademia>Wikademia at 06:51, 16 May 2009

2009-05-16T06:51:43Z

← Older revision		Revision as of 06:51, 16 May 2009
Line 4:		Line 4:

	=== 16.1 Time ===		=== 16.1 Time ===
			{{?}}
	As another example of a user-defined type, we'll define a class called		As another example of a user-defined type, we'll define a class called
	<TT>Time</TT> that records the time of day. The class definition looks		<TT>Time</TT> that records the time of day. The class definition looks
Line 17:		Line 17:
	We can create a new <TT>Time</TT> object and assign		We can create a new <TT>Time</TT> object and assign
	attributes for hours, minutes, and seconds:		attributes for hours, minutes, and seconds:

	<code>		<code>
	time = Time()		time = Time()

wikademia>Wikademia: 8 revisions

2009-05-11T20:43:29Z

8 revisions

← Older revision	Revision as of 20:43, 11 May 2009
(No difference)

wikademia>Magicbadger at 21:35, 6 October 2008

2008-10-06T21:35:56Z

← Older revision		Revision as of 21:35, 6 October 2008
Line 368:		Line 368:
	minutes and seconds until their next birthday.		minutes and seconds until their next birthday.
	''		''

	~~</DIV><HR>~~
	~~<IMG SRC="previous_motif.gif" ALT="Previous">~~
	~~<IMG SRC="contents_motif.gif" ALT="Up">~~
	~~<IMG SRC="next_motif.gif" ALT="Next">~~

wikademia>Magicbadger: /* 16.3 Modifiers */

2008-10-06T21:34:29Z

16.3 Modifiers

← Older revision		Revision as of 21:34, 6 October 2008
Line 174:		Line 174:
	Write a &#X201C;pure&#X201D; version of ''''<TT>increment</TT>'''' that creates and returns		Write a &#X201C;pure&#X201D; version of ''''<TT>increment</TT>'''' that creates and returns
	a new Time object rather than modifying the parameter.		a new Time object rather than modifying the parameter.
	~~''</DIV>~~=== 16.4~~&#XA0;&#XA0;~~Prototyping versus planning ===
			=== 16.4 Prototyping versus planning ===


Line 264:		Line 265:
	easier (because there are fewer special cases and fewer opportunities		easier (because there are fewer special cases and fewer opportunities
	for error).		for error).

	=== 16.5&#XA0;&#XA0;Debugging ===		=== 16.5&#XA0;&#XA0;Debugging ===

wikademia>Magicbadger: /* Exercise 2 */

2008-10-06T21:33:42Z

Exercise 2

← Older revision		Revision as of 21:33, 6 October 2008
Line 40:		Line 40:
	==== Exercise 2 ====		==== Exercise 2 ====

	''Write a boolean function called <code>is_after</code> that		Write a boolean function called <code>is_after</code> that
	takes two Time objects, <code>t1</code> and <code>t2</code>, and		takes two Time objects, <code>t1</code> and <code>t2</code>, and
	returns <code>True</code> if <code>t1</code> follows <code>t2</code>		returns <code>True</code> if <code>t1</code> follows <code>t2</code>
	chronologically and <code>False</code> otherwise.		chronologically and <code>False</code> otherwise.

	Challenge: don't use an <code>if</code> statement.''		Challenge: don't use an <code>if</code> statement.

	=== 16.2 Pure functions ===		=== 16.2 Pure functions ===

wikademia>Magicbadger: /* Exercise 1 */

2008-10-06T21:33:19Z

Exercise 1

← Older revision		Revision as of 21:33, 6 October 2008
Line 32:		Line 32:
	==== Exercise 1 ====		==== Exercise 1 ====

	''Write a function called <code>print_time</code> that takes a		Write a function called <code>print_time</code> that takes a
	Time object and prints it in the form <code>hour:minute:second</code>.''		Time object and prints it in the form <code>hour:minute:second</code>.

	Hint: the format sequence <code>%.2d</code> prints an integer using		Hint: the format sequence <code>%.2d</code> prints an integer using

wikademia>Magicbadger: /* Chapter 16 Classes and functions */

2008-10-06T21:32:47Z

Chapter 16 Classes and functions

← Older revision		Revision as of 21:32, 6 October 2008
Line 2:		Line 2:

	== Chapter 16 Classes and functions ==		== Chapter 16 Classes and functions ==



	=== 16.1 Time ===		=== 16.1 Time ===
Line 11:		Line 9:
	like this:		like this:

	<~~PRE CLASS="verbatim"~~>class Time(object):		<code>
			class Time(object):
	"""represents the time of day.		"""represents the time of day.
	attributes: hour, minute, second"""		attributes: hour, minute, second"""
	</~~PRE~~>		</code>

	We can create a new <TT>Time</TT> object and assign		We can create a new <TT>Time</TT> object and assign
	attributes for hours, minutes, and seconds:		attributes for hours, minutes, and seconds:
	<~~PRE CLASS="verbatim"~~>time = Time()
			<code>
			time = Time()
	time.hour = 11		time.hour = 11
	time.minute = 59		time.minute = 59
	time.second = 30		time.second = 30
	</~~PRE~~>		</code>

	The state diagram for the <TT>Time</TT> object looks like this:		The state diagram for the <TT>Time</TT> object looks like this:


	<DIV CLASS="center"><IMG SRC="book025.png"></DIV><DIV CLASS="theorem">~~'''~~Exercise~~&#XA0;~~1~~'''&#XA0;&#XA0;''~~		<DIV CLASS="center"><IMG SRC="book025.png"></DIV><DIV CLASS="theorem">
	''''
	Write a function called ''<~~CODE~~>''print_time''</~~CODE~~>'' that takes a		==== Exercise 1 ====
	Time object and prints it in the form ~~''''~~<TT>hour:minute:second</TT>''~~''.~~
	Hint: the format sequence ''<~~CODE~~>~~'''~~%.2d~~'''~~</~~CODE~~>'' prints an integer using		''Write a function called <code>print_time</code> that takes a
			Time object and prints it in the form <code>hour:minute:second</code>.''

			Hint: the format sequence <code>%.2d</code> prints an integer using
	at least two digits, including a leading zero if necessary.		at least two digits, including a leading zero if necessary.
	~~''</DIV><DIV CLASS="theorem">'''Exercise&#XA0;2'''&#XA0;&#XA0;''~~
	''

	~~''Write a boolean function called ''<CODE>''is_after''</CODE>'' that~~		==== Exercise 2 ====
	~~takes two Time objects, ''''<TT>t1</TT>'''' and ''''<TT>t2</TT>'''', and~~
	~~returns ''''<TT>True</TT>'''' if ''''<TT>t1</TT>'''' follows ''''<TT>t2</TT>'''' chronologically and~~
	~~''''<TT>False</TT>'''' otherwise. Challenge: don&#X2019;t use an ''''<TT>if</TT>'''' statement.~~
	''
	~~</DIV>~~=== ~~16.~~2~~&#XA0;&#XA0;Pure functions~~ ===

			''Write a boolean function called <code>is_after</code> that
			takes two Time objects, <code>t1</code> and <code>t2</code>, and
			returns <code>True</code> if <code>t1</code> follows <code>t2</code>
			chronologically and <code>False</code> otherwise.

			Challenge: don't use an <code>if</code> statement.''

			=== 16.2 Pure functions ===

	In the next few sections, we&#X2019;ll write two functions that add time		In the next few sections, we&#X2019;ll write two functions that add time

82.32.51.70: /* Chapter 16 Classes and functions */

2008-10-06T21:26:32Z

Chapter 16 Classes and functions

← Older revision		Revision as of 21:26, 6 October 2008
Line 1:		Line 1:
	{{Think Python/Page}}		{{Think Python/Page}}

	== Chapter~~&#XA0;~~16~~&#XA0;&#XA0;~~Classes and functions ==		== Chapter 16 Classes and functions ==



	=== 16.1~~&#XA0;&#XA0;~~Time ===		=== 16.1 Time ===

	As another example of a user-defined type, we~~&#X2019;~~ll define a class called		As another example of a user-defined type, we'll define a class called
	<TT>Time</TT> that records the time of day. The class definition looks		<TT>Time</TT> that records the time of day. The class definition looks
	like this:		like this:





	<PRE CLASS="verbatim">class Time(object):		<PRE CLASS="verbatim">class Time(object):
Line 27:		Line 23:
	</PRE>		</PRE>
	The state diagram for the <TT>Time</TT> object looks like this:		The state diagram for the <TT>Time</TT> object looks like this:

wikademia>Whiteknight: Partial (mostly) conversion from HTML to Wikitext

2008-09-15T23:09:55Z

Partial (mostly) conversion from HTML to Wikitext

Show changes