diff options
Diffstat (limited to 'Doc/tutorial')
| -rw-r--r-- | Doc/tutorial/inputoutput.rst | 39 |
1 files changed, 19 insertions, 20 deletions
diff --git a/Doc/tutorial/inputoutput.rst b/Doc/tutorial/inputoutput.rst index b35cc80..00f5aea 100644 --- a/Doc/tutorial/inputoutput.rst +++ b/Doc/tutorial/inputoutput.rst @@ -40,8 +40,8 @@ which can be read by the interpreter (or will force a :exc:`SyntaxError` if there is not equivalent syntax). For objects which don't have a particular representation for human consumption, :func:`str` will return the same value as :func:`repr`. Many values, such as numbers or structures like lists and -dictionaries, have the same representation using either function. Strings and -floating point numbers, in particular, have two distinct representations. +dictionaries, have the same representation using either function. Strings, in +particular, have two distinct representations. Some examples:: @@ -50,9 +50,7 @@ Some examples:: 'Hello, world.' >>> repr(s) "'Hello, world.'" - >>> str(1.0/7.0) - '0.142857142857' - >>> repr(1.0/7.0) + >>> str(1/7) '0.14285714285714285' >>> x = 10 * 3.25 >>> y = 200 * 200 @@ -103,17 +101,18 @@ Here are two ways to write a table of squares and cubes:: (Note that in the first example, one space between each column was added by the way :func:`print` works: it always adds spaces between its arguments.) -This example demonstrates the :meth:`rjust` method of string objects, which -right-justifies a string in a field of a given width by padding it with spaces -on the left. There are similar methods :meth:`ljust` and :meth:`center`. These -methods do not write anything, they just return a new string. If the input -string is too long, they don't truncate it, but return it unchanged; this will -mess up your column lay-out but that's usually better than the alternative, -which would be lying about a value. (If you really want truncation you can -always add a slice operation, as in ``x.ljust(n)[:n]``.) +This example demonstrates the :meth:`str.rjust` method of string +objects, which right-justifies a string in a field of a given width by padding +it with spaces on the left. There are similar methods :meth:`str.ljust` and +:meth:`str.center`. These methods do not write anything, they just return a +new string. If the input string is too long, they don't truncate it, but +return it unchanged; this will mess up your column lay-out but that's usually +better than the alternative, which would be lying about a value. (If you +really want truncation you can always add a slice operation, as in +``x.ljust(n)[:n]``.) -There is another method, :meth:`zfill`, which pads a numeric string on the left -with zeros. It understands about plus and minus signs:: +There is another method, :meth:`str.zfill`, which pads a numeric string on the +left with zeros. It understands about plus and minus signs:: >>> '12'.zfill(5) '00012' @@ -128,16 +127,16 @@ Basic usage of the :meth:`str.format` method looks like this:: We are the knights who say "Ni!" The brackets and characters within them (called format fields) are replaced with -the objects passed into the :meth:`~str.format` method. A number in the +the objects passed into the :meth:`str.format` method. A number in the brackets can be used to refer to the position of the object passed into the -:meth:`~str.format` method. :: +:meth:`str.format` method. :: >>> print('{0} and {1}'.format('spam', 'eggs')) spam and eggs >>> print('{1} and {0}'.format('spam', 'eggs')) eggs and spam -If keyword arguments are used in the :meth:`~str.format` method, their values +If keyword arguments are used in the :meth:`str.format` method, their values are referred to by using the name of the argument. :: >>> print('This {food} is {adjective}.'.format( @@ -195,8 +194,8 @@ notation. :: >>> print('Jack: {Jack:d}; Sjoerd: {Sjoerd:d}; Dcab: {Dcab:d}'.format(**table)) Jack: 4098; Sjoerd: 4127; Dcab: 8637678 -This is particularly useful in combination with the new built-in :func:`vars` -function, which returns a dictionary containing all local variables. +This is particularly useful in combination with the built-in function +:func:`vars`, which returns a dictionary containing all local variables. For a complete overview of string formatting with :meth:`str.format`, see :ref:`formatstrings`. |