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Diffstat (limited to 'shar/python-0.9.1-01-21.shar')
| -rw-r--r-- | shar/python-0.9.1-01-21.shar | 163 |
1 files changed, 87 insertions, 76 deletions
diff --git a/shar/python-0.9.1-01-21.shar b/shar/python-0.9.1-01-21.shar index 7b00e8a..e3d0436 100644 --- a/shar/python-0.9.1-01-21.shar +++ b/shar/python-0.9.1-01-21.shar @@ -1,3 +1,14 @@ +Path: funic!news.funet.fi!sunic!mcsun!hp4nl!charon!guido +From: [email protected] (Guido van Rossum) +Newsgroups: alt.sources +Subject: Python 0.9.1 part 01/21 +Message-ID: <[email protected]> +Date: 19 Feb 91 17:35:26 GMT +Sender: [email protected] +Organization: CWI, Amsterdam +Lines: 1952 +Originator: [email protected] + : This is a shell archive. : Extract with 'sh this_file'. : Extract this part first since it makes all directories @@ -71,7 +82,7 @@ X Kruislaan 413 X 1098 SJ Amsterdam X The Netherlands X -X E-mail: [email protected] +X E-mail: [email protected] X XThe Python source is copyrighted, but you can freely use and copy it Xas long as you don't change or remove the copyright: @@ -82,10 +93,10 @@ XNetherlands. X X All Rights Reserved X -XPermission to use, copy, modify, and distribute this software and its -Xdocumentation for any purpose and without fee is hereby granted, +XPermission to use, copy, modify, and distribute this software and its +Xdocumentation for any purpose and without fee is hereby granted, Xprovided that the above copyright notice appear in all copies and that -Xboth that copyright notice and this permission notice appear in +Xboth that copyright notice and this permission notice appear in Xsupporting documentation, and that the names of Stichting Mathematisch XCentrum or CWI not be used in advertising or publicity pertaining to Xdistribution of the software without specific, written prior permission. @@ -162,7 +173,7 @@ XKruislaan 413 X1098 SJ Amsterdam XThe Netherlands X.PP -XE-mail: [email protected] +XE-mail: [email protected] X.fi X.SH COPYRIGHT XCopyright 1991 by Stichting Mathematisch Centrum, Amsterdam, The @@ -170,10 +181,10 @@ XNetherlands. X.IP " " XAll Rights Reserved X.PP -XPermission to use, copy, modify, and distribute this software and its -Xdocumentation for any purpose and without fee is hereby granted, +XPermission to use, copy, modify, and distribute this software and its +Xdocumentation for any purpose and without fee is hereby granted, Xprovided that the above copyright notice appear in all copies and that -Xboth that copyright notice and this permission notice appear in +Xboth that copyright notice and this permission notice appear in Xsupporting documentation, and that the names of Stichting Mathematisch XCentrum or CWI not be used in advertising or publicity pertaining to Xdistribution of the software without specific, written prior permission. @@ -402,15 +413,15 @@ X%\documentstyle[garamond,11pt,myformat]{article} X\documentstyle[11pt,myformat]{article} X X\title{\bf -X Python Tutorial \\ -X (DRAFT) +X Python Tutorial \\ +X (DRAFT) X} X X\author{ X Guido van Rossum \\ X Dept. CST, CWI, Kruislaan 413 \\ X 1098 SJ Amsterdam, The Netherlands \\ -X E-mail: {\tt [email protected]} +X E-mail: {\tt [email protected]} X} X X\begin{document} @@ -759,13 +770,13 @@ X\bcode\begin{verbatim} X>>> # This is a comment X>>> 2+2 X4 -X>>> +X>>> X>>> (50-5+5*6+25)/4 X25 X>>> # Division truncates towards zero: X>>> 7/3 X2 -X>>> +X>>> X\end{verbatim}\ecode XAs in C, the equal sign ({\tt =}) is used to assign a value to a variable. XThe value of an assignment is not written: @@ -774,14 +785,14 @@ X>>> width = 20 X>>> height = 5*9 X>>> width * height X900 -X>>> +X>>> X\end{verbatim}\ecode XThere is some support for floating point, but you can't mix floating Xpoint and integral numbers in expression (yet): X\bcode\begin{verbatim} X>>> 10.0 / 3.3 X3.0303030303 -X>>> +X>>> X\end{verbatim}\ecode XBesides numbers, \Python\ can also manipulate strings, enclosed in single Xquotes: @@ -790,7 +801,7 @@ X>>> 'foo bar' X'foo bar' X>>> 'doesn\'t' X'doesn\'t' -X>>> +X>>> X\end{verbatim}\ecode XStrings are written inside quotes and with quotes and other funny Xcharacters escaped by backslashes, to show the precise value. @@ -804,7 +815,7 @@ X>>> word X'HelpA' X>>> '<' + word*5 + '>' X'<HelpAHelpAHelpAHelpAHelpA>' -X>>> +X>>> X\end{verbatim}\ecode XStrings can be subscripted; as in C, the first character of a string has Xsubscript 0. @@ -828,7 +839,7 @@ X'lpA' X>>> # A useful invariant: s[:i] + s[i:] = s X>>> word[:3] + word[3:] X'HelpA' -X>>> +X>>> X\end{verbatim}\ecode XDegenerate cases are handled gracefully: an index that is too large is Xreplaced by the string size, an upper bound smaller than the lower bound @@ -840,7 +851,7 @@ X>>> word[10:] X'' X>>> word[2:1] X'' -X>>> +X>>> X\end{verbatim}\ecode XSlice indices (but not simple subscripts) may be negative numbers, to Xstart counting from the right. @@ -853,7 +864,7 @@ X'Hel' X>>> # But -0 does not count from the right! X>>> word[-0:] # (since -0 equals 0) X'HelpA' -X>>> +X>>> X\end{verbatim}\ecode XThe best way to remember how slices work is to think of the indices as Xpointing @@ -865,10 +876,10 @@ Xcharacters has index X{\tt n}, Xfor example: X\bcode\begin{verbatim} -X +---+---+---+---+---+ +X +---+---+---+---+---+ X | H | e | l | p | A | -X +---+---+---+---+---+ -X 0 1 2 3 4 5 +X +---+---+---+---+---+ +X 0 1 2 3 4 5 X-5 -4 -3 -2 -1 X\end{verbatim}\ecode XThe first row of numbers gives the position of the indices 0...5 in the @@ -886,7 +897,7 @@ X\bcode\begin{verbatim} X>>> s = 'supercalifragilisticexpialidocious' X>>> len(s) X34 -X>>> +X>>> X\end{verbatim}\ecode X\Python\ knows a number of X{\em compound} @@ -899,7 +910,7 @@ X\bcode\begin{verbatim} X>>> a = ['foo', 'bar', 100, 1234] X>>> a X['foo', 'bar', 100, 1234] -X>>> +X>>> X\end{verbatim}\ecode XAs for strings, list subscripts start at 0: X\bcode\begin{verbatim} @@ -907,7 +918,7 @@ X>>> a[0] X'foo' X>>> a[3] X1234 -X>>> +X>>> X\end{verbatim}\ecode XLists can be sliced and concatenated like strings: X\bcode\begin{verbatim} @@ -915,7 +926,7 @@ X>>> a[1:3] X['bar', 100] X>>> a[:2] + ['bletch', 2*2] X['foo', 'bar', 'bletch', 4] -X>>> +X>>> X\end{verbatim}\ecode XUnlike strings, which are X{\em immutable}, @@ -943,13 +954,13 @@ X>>> # Insert some: X>>> a[1:1] = ['bletch', 'xyzzy'] X>>> a X[123, 'bletch', 'xyzzy', 1234] -X>>> +X>>> X\end{verbatim}\ecode XThe built-in function {\tt len()} also applies to lists: X\bcode\begin{verbatim} X>>> len(a) X4 -X>>> +X>>> X\end{verbatim}\ecode X X\subsection{Tuples and Sequences} @@ -970,7 +981,7 @@ X>>> a, b = 0, 1 X>>> while b < 100: X... print b X... a, b = b, a+b -X... +X... X1 X1 X2 @@ -982,7 +993,7 @@ X21 X34 X55 X89 -X>>> +X>>> X\end{verbatim}\ecode XThis example introduces several new features. X\begin{itemize} @@ -1043,7 +1054,7 @@ X\bcode\begin{verbatim} X>>> i = 256*256 X>>> print 'The value of i is', i XThe value of i is 65536 -X>>> +X>>> X\end{verbatim}\ecode XA trailing comma avoids the newline after the output: X\bcode\begin{verbatim} @@ -1051,9 +1062,9 @@ X>>> a, b = 0, 1 X>>> while b < 1000: X... print b, X... a, b = b, a+b -X... +X... X1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987 -X>>> +X>>> X\end{verbatim}\ecode XNote that the interpreter inserts a newline before it prints the next Xprompt if the last line was not completed. @@ -1079,7 +1090,7 @@ X... elif x = 1: X... print 'Single' X... else: X... print 'More' -X... +X... X\end{verbatim}\ecode XThere can be zero or more {\tt elif} parts, and the {\tt else} part is Xoptional. @@ -1102,11 +1113,11 @@ X>>> # Measure some strings: X>>> a = ['cat', 'window', 'defenestrate'] X>>> for x in a: X... print x, len(x) -X... +X... Xcat 3 Xwindow 6 Xdefenestrate 12 -X>>> +X>>> X\end{verbatim}\ecode X X\subsubsection{The {\tt range()} Function} @@ -1118,7 +1129,7 @@ Xe.g.: X\bcode\begin{verbatim} X>>> range(10) X[0, 1, 2, 3, 4, 5, 6, 7, 8, 9] -X>>> +X>>> X\end{verbatim}\ecode XThe given end point is never part of the generated list; X{\tt range(10)} generates a list of 10 values, @@ -1132,7 +1143,7 @@ X>>> range(0, 10, 3) X[0, 3, 6, 9] X>>> range(-10, -100, -30) X[-10, -40, -70] -X>>> +X>>> X\end{verbatim}\ecode XTo iterate over the indices of a sequence, combine {\tt range()} Xand {\tt len()} as follows: @@ -1140,13 +1151,13 @@ X\bcode\begin{verbatim} X>>> a = ['Mary', 'had', 'a', 'little', 'boy'] X>>> for i in range(len(a)): X... print i, a[i] -X... +X... X0 Mary X1 had X2 a X3 little X4 boy -X>>> +X>>> X\end{verbatim}\ecode X X\subsubsection{Break Statements and Else Clauses on Loops} @@ -1167,7 +1178,7 @@ X... print n, 'equals', x, '*', n/x X... break X... else: X... print n, 'is a prime number' -X... +X... X2 is a prime number X3 is a prime number X4 equals 2 * 2 @@ -1176,7 +1187,7 @@ X6 equals 2 * 3 X7 is a prime number X8 equals 2 * 4 X9 equals 3 * 3 -X>>> +X>>> X\end{verbatim}\ecode X X\subsubsection{Pass Statements} @@ -1188,7 +1199,7 @@ XFor example: X\bcode\begin{verbatim} X>>> while 1: X... pass # Busy-wait for keyboard interrupt -X... +X... X\end{verbatim}\ecode X X\subsubsection{Conditions Revisited} @@ -1205,11 +1216,11 @@ X... a, b = 0, 1 X... while b <= n: X... print b, X... a, b = b, a+b -X... +X... X>>> # Now call the function we just defined: X>>> fib(2000) X1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987 1597 -X>>> +X>>> X\end{verbatim}\ecode XThe keyword X{\tt def} @@ -1256,7 +1267,7 @@ X<function object at 10042ed0> X>>> f = fib X>>> f(100) X1 1 2 3 5 8 13 21 34 55 89 -X>>> +X>>> X\end{verbatim}\ecode XYou might object that X{\tt fib} @@ -1272,7 +1283,7 @@ XYou can see it if you really want to: X\bcode\begin{verbatim} X>>> print fib(0) XNone -X>>> +X>>> X\end{verbatim}\ecode XIt is simple to write a function that returns a list of the numbers of Xthe Fibonacci series, instead of printing it: @@ -1284,11 +1295,11 @@ X... while b <= n: X... result.append(b) # see below X... a, b = b, a+b X... return result -X... +X... X>>> f100 = fib2(100) # call it X>>> f100 # write the result X[1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89] -X>>> +X>>> X\end{verbatim}\ecode XThis example, as usual, demonstrates some new \Python\ features: X\begin{itemize} @@ -1354,7 +1365,7 @@ X>>> b = ['Mary', 'had', 'a', 'little', 'boy'] X>>> b.sort() X>>> b X['Mary', 'a', 'boy', 'had', 'little'] -X>>> +X>>> X\end{verbatim}\ecode X X\subsection{Modules} @@ -1409,7 +1420,7 @@ XNow enter the \Python\ interpreter and import this module with the Xfollowing command: X\bcode\begin{verbatim} X>>> import fibo -X>>> +X>>> X\end{verbatim}\ecode XThis does not enter the names of the functions defined in X{\tt fibo} @@ -1422,14 +1433,14 @@ X>>> fibo.fib(1000) X1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987 X>>> fibo.fib2(100) X[1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89] -X>>> +X>>> X\end{verbatim}\ecode XIf you intend to use a function often you can assign it to a local name: X\bcode\begin{verbatim} X>>> fib = fibo.fib X>>> fib(500) X1 1 2 3 5 8 13 21 34 55 89 144 233 377 -X>>> +X>>> X\end{verbatim}\ecode X X\subsubsection{More on Modules} @@ -1472,7 +1483,7 @@ X\bcode\begin{verbatim} X>>> from fibo import fib, fib2 X>>> fib(500) X1 1 2 3 5 8 13 21 34 55 89 144 233 377 -X>>> +X>>> X\end{verbatim}\ecode XThis does not introduce the module name from which the imports are taken Xin the local symbol table (so in the example, {\tt fibo} is not @@ -1483,7 +1494,7 @@ X\bcode\begin{verbatim} X>>> from fibo import * X>>> fib(500) X1 1 2 3 5 8 13 21 34 55 89 144 233 377 -X>>> +X>>> X\end{verbatim}\ecode XThis imports all names except those beginning with an underscore X({\tt \_}). @@ -1517,7 +1528,7 @@ X'... ' X>>> sys.ps1 = 'C> ' XC> print 'Yuck!' XYuck! -XC> +XC> X\end{verbatim}\ecode XThese two variables are only defined if the interpreter is in Xinteractive mode. @@ -1535,7 +1546,7 @@ XYou can modify it using standard list operations, e.g.: X\bcode\begin{verbatim} X>>> import sys X>>> sys.path.append('/ufs/guido/lib/python') -X>>> +X>>> X\end{verbatim}\ecode X X\subsection{Errors and Exceptions} @@ -1557,7 +1568,7 @@ XParsing error: file <stdin>, line 1: Xwhile 1 print 'Hello world' X ^ XUnhandled exception: run-time error: syntax error -X>>> +X>>> X\end{verbatim}\ecode XThe parser repeats the offending line and displays a little `arrow' Xpointing at the earliest point in the line where the error was detected. @@ -1585,7 +1596,7 @@ X>>> '2' + 2 XUnhandled exception: type error: illegal argument type for built-in operation XStack backtrace (innermost last): X File "<stdin>", line 1 -X>>> +X>>> X\end{verbatim}\ecode XErrors detected during execution are called X{\em exceptions} @@ -1647,12 +1658,12 @@ X... try: X... print 1.0 / x X... except RuntimeError: X... print '*** has no inverse ***' -X... +X... X0.3333 3.00030003 X2.5 0.4 X0 *** has no inverse *** X10 0.1 -X>>> +X>>> X\end{verbatim}\ecode XThe {\tt try} statement works as follows. X\begin{itemize} @@ -1704,9 +1715,9 @@ X>>> try: X... foo() X... except NameError, x: X... print 'name', x, 'undefined' -X... +X... Xname foo undefined -X>>> +X>>> X\end{verbatim}\ecode XIf an exception has an argument, it is printed as the third part X(`detail') of the message for unhandled exceptions. @@ -1743,14 +1754,14 @@ XFor example: X\bcode\begin{verbatim} X>>> def this_fails(): X... x = 1/0 -X... +X... X>>> try: X... this_fails() X... except RuntimeError, detail: X... print 'Handling run-time error:', detail -X... +X... XHandling run-time error: domain error or zero division -X>>> +X>>> X\end{verbatim}\ecode X X\subsubsection{Raising Exceptions} @@ -1763,7 +1774,7 @@ X>>> raise NameError, 'Hi There!' XUnhandled exception: undefined name: Hi There! XStack backtrace (innermost last): X File "<stdin>", line 1 -X>>> +X>>> X\end{verbatim}\ecode XThe first argument to {\tt raise} names the exception to be raised. XThe optional second argument specifies the exception's argument. @@ -1779,13 +1790,13 @@ X>>> try: X... raise my_exc, 2*2 X... except my_exc, val: X... print 'My exception occured, value:', val -X... +X... XMy exception occured, value: 4 X>>> raise my_exc, 1 XUnhandled exception: nobody likes me!: 1 XStack backtrace (innermost last): X File "<stdin>", line 7 -X>>> +X>>> X\end{verbatim}\ecode XMany standard modules use this to report errors that may occur in Xfunctions they define. @@ -1800,12 +1811,12 @@ X>>> try: X... raise KeyboardInterrupt X... finally: X... print 'Goodbye, world!' -X... +X... XGoodbye, world! XUnhandled exception: keyboard interrupt XStack backtrace (innermost last): X File "<stdin>", line 2 -X>>> +X>>> X\end{verbatim}\ecode XThe X{\em finally\ clause} @@ -1904,18 +1915,18 @@ X>>> a.add(3) X>>> a.add(1) X>>> a.add(1) X>>> if a.is_element(3): print '3 is in the set' -X... +X... X3 is in the set X>>> if not a.is_element(4): print '4 is not in the set' -X... +X... X4 is not in the set X>>> print 'a has', a.size(), 'elements' Xa has 3 elements X>>> a.remove(1) X>>> print 'now a has', a.size(), 'elements' -X>>> +X>>> Xnow a has 2 elements -X>>> +X>>> X\end{verbatim}\ecode XFrom the example we learn in the first place that the functions defined Xin the class (e.g., |