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authorGeorg Brandl <georg@python.org>2008-09-13 17:18:11 (GMT)
committerGeorg Brandl <georg@python.org>2008-09-13 17:18:11 (GMT)
commit3ce0dee9a3a5bce536ddab38bf233deaaded00e0 (patch)
treeab60a82f95343b2ea1a58a92291b65550eff9870
parenta9aff014a86d40924e9f44f62cec2632b53ede11 (diff)
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Incorporate some suggestions by Tait Stevens.
-rw-r--r--Doc/tutorial/classes.rst2
-rw-r--r--Doc/tutorial/controlflow.rst49
-rw-r--r--Doc/tutorial/datastructures.rst1
-rw-r--r--Doc/tutorial/introduction.rst17
4 files changed, 42 insertions, 27 deletions
diff --git a/Doc/tutorial/classes.rst b/Doc/tutorial/classes.rst
index bca9108..43f2c6d 100644
--- a/Doc/tutorial/classes.rst
+++ b/Doc/tutorial/classes.rst
@@ -208,7 +208,7 @@ the class's namespace when the class object was created. So, if the class
definition looked like this::
class MyClass:
- "A simple example class"
+ """A simple example class"""
i = 12345
def f(self):
return 'hello world'
diff --git a/Doc/tutorial/controlflow.rst b/Doc/tutorial/controlflow.rst
index 4fa9858..a77618f 100644
--- a/Doc/tutorial/controlflow.rst
+++ b/Doc/tutorial/controlflow.rst
@@ -17,6 +17,7 @@ Perhaps the most well-known statement type is the :keyword:`if` statement. For
example::
>>> x = int(raw_input("Please enter an integer: "))
+ Please enter an integer: 42
>>> if x < 0:
... x = 0
... print 'Negative changed to zero'
@@ -26,7 +27,8 @@ example::
... print 'Single'
... else:
... print 'More'
- ...
+ ...
+ More
There can be zero or more :keyword:`elif` parts, and the :keyword:`else` part is
optional. The keyword ':keyword:`elif`' is short for 'else if', and is useful
@@ -161,7 +163,7 @@ The :keyword:`pass` statement does nothing. It can be used when a statement is
required syntactically but the program requires no action. For example::
>>> while True:
- ... pass # Busy-wait for keyboard interrupt
+ ... pass # Busy-wait for keyboard interrupt (Ctrl+C)
...
@@ -192,14 +194,14 @@ boundary::
The keyword :keyword:`def` introduces a function *definition*. It must be
followed by the function name and the parenthesized list of formal parameters.
The statements that form the body of the function start at the next line, and
-must be indented. The first statement of the function body can optionally be a
-string literal; this string literal is the function's documentation string, or
-:dfn:`docstring`.
+must be indented.
+The first statement of the function body can optionally be a string literal;
+this string literal is the function's documentation string, or :dfn:`docstring`.
+(More about docstrings can be found in the section :ref:`tut-docstrings`.)
There are tools which use docstrings to automatically produce online or printed
documentation, or to let the user interactively browse through code; it's good
-practice to include docstrings in code that you write, so try to make a habit of
-it.
+practice to include docstrings in code that you write, so make a habit of it.
The *execution* of a function introduces a new symbol table used for the local
variables of the function. More precisely, all variable assignments in a
@@ -228,12 +230,12 @@ mechanism::
>>> f(100)
1 1 2 3 5 8 13 21 34 55 89
-You might object that ``fib`` is not a function but a procedure. In Python,
-like in C, procedures are just functions that don't return a value. In fact,
-technically speaking, procedures do return a value, albeit a rather boring one.
-This value is called ``None`` (it's a built-in name). Writing the value
-``None`` is normally suppressed by the interpreter if it would be the only value
-written. You can see it if you really want to using :keyword:`print`::
+Coming from other languages, you might object that ``fib`` is not a function but
+a procedure since it doesn't return a value. In fact, even functions without a
+:keyword:`return` statement do return a value, albeit a rather boring one. This
+value is called ``None`` (it's a built-in name). Writing the value ``None`` is
+normally suppressed by the interpreter if it would be the only value written.
+You can see it if you really want to using :keyword:`print`::
>>> fib(0)
>>> print fib(0)
@@ -259,7 +261,7 @@ This example, as usual, demonstrates some new Python features:
* The :keyword:`return` statement returns with a value from a function.
:keyword:`return` without an expression argument returns ``None``. Falling off
- the end of a procedure also returns ``None``.
+ the end of a function also returns ``None``.
* The statement ``result.append(b)`` calls a *method* of the list object
``result``. A method is a function that 'belongs' to an object and is named
@@ -400,21 +402,21 @@ list. (``*name`` must occur before ``**name``.) For example, if we define a
function like this::
def cheeseshop(kind, *arguments, **keywords):
- print "-- Do you have any", kind, '?'
+ print "-- Do you have any", kind, "?"
print "-- I'm sorry, we're all out of", kind
for arg in arguments: print arg
- print '-'*40
+ print "-" * 40
keys = keywords.keys()
keys.sort()
- for kw in keys: print kw, ':', keywords[kw]
+ for kw in keys: print kw, ":", keywords[kw]
It could be called like this::
- cheeseshop('Limburger', "It's very runny, sir.",
+ cheeseshop("Limburger", "It's very runny, sir.",
"It's really very, VERY runny, sir.",
- client='John Cleese',
shopkeeper='Michael Palin',
- sketch='Cheese Shop Sketch')
+ client="John Cleese",
+ sketch="Cheese Shop Sketch")
and of course it would print::
@@ -442,8 +444,8 @@ Arbitrary Argument Lists
Finally, the least frequently used option is to specify that a function can be
called with an arbitrary number of arguments. These arguments will be wrapped
-up in a tuple. Before the variable number of arguments, zero or more normal
-arguments may occur. ::
+up in a tuple (see :ref:`tut-tuples`). Before the variable number of arguments,
+zero or more normal arguments may occur. ::
def write_multiple_items(file, separator, *args):
file.write(separator.join(args))
@@ -600,7 +602,8 @@ extracted for you:
* Name your classes and functions consistently; the convention is to use
``CamelCase`` for classes and ``lower_case_with_underscores`` for functions
- and methods. Always use ``self`` as the name for the first method argument.
+ and methods. Always use ``self`` as the name for the first method argument
+ (see :ref:`tut-firstclasses` for more on classes and methods).
* Don't use fancy encodings if your code is meant to be used in international
environments. Plain ASCII works best in any case.
diff --git a/Doc/tutorial/datastructures.rst b/Doc/tutorial/datastructures.rst
index fa71870..931f506 100644
--- a/Doc/tutorial/datastructures.rst
+++ b/Doc/tutorial/datastructures.rst
@@ -345,6 +345,7 @@ of an empty list to the slice). For example::
Referencing the name ``a`` hereafter is an error (at least until another value
is assigned to it). We'll find other uses for :keyword:`del` later.
+.. _tut-tuples:
.. _tut-tuples:
diff --git a/Doc/tutorial/introduction.rst b/Doc/tutorial/introduction.rst
index c138ce6..797e531 100644
--- a/Doc/tutorial/introduction.rst
+++ b/Doc/tutorial/introduction.rst
@@ -13,9 +13,11 @@ end a multi-line command.
Many of the examples in this manual, even those entered at the interactive
prompt, include comments. Comments in Python start with the hash character,
-``#``, and extend to the end of the physical line. A comment may appear at
-the start of a line or following whitespace or code, but not within a string
+``#``, and extend to the end of the physical line. A comment may appear at the
+start of a line or following whitespace or code, but not within a string
literal. A hash character within a string literal is just a hash character.
+Since comments are to clarify code and are not interpreted by Python, they may
+be omitted when typing in examples.
Some examples::
@@ -77,6 +79,15 @@ A value can be assigned to several variables simultaneously::
>>> z
0
+Variables must be "defined" (assigned a value) before they can be used, or an
+error will occur::
+
+ >>> # try to access an undefined variable
+ ... n
+ Traceback (most recent call last):
+ File "<stdin>", line 1, in <module>
+ NameError: name 'n' is not defined
+
There is full support for floating point; operators with mixed type operands
convert the integer operand to floating point::
@@ -269,7 +280,7 @@ omitted second index defaults to the size of the string being sliced. ::
>>> word[2:] # Everything except the first two characters
'lpA'
-Unlike a C string, Python strings cannot be changed. Assigning to an indexed
+Unlike a C string, Python strings cannot be changed. Assigning to an indexed
position in the string results in an error::
>>> word[0] = 'x'