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author | R David Murray <rdmurray@bitdance.com> | 2013-06-19 20:59:22 (GMT) |
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committer | R David Murray <rdmurray@bitdance.com> | 2013-06-19 20:59:22 (GMT) |
commit | 2f72aed1b40d9f88361e07bd83b14edc7e305c39 (patch) | |
tree | 60af87fcc0c0252f4af059510b549cb504df7cdf | |
parent | 15a7d2e8d6cde1acedbe7b0c9991c72db9c16883 (diff) | |
parent | fdf95030389bfd3e8ecf5e9760fb9926705809d4 (diff) | |
download | cpython-2f72aed1b40d9f88361e07bd83b14edc7e305c39.zip cpython-2f72aed1b40d9f88361e07bd83b14edc7e305c39.tar.gz cpython-2f72aed1b40d9f88361e07bd83b14edc7e305c39.tar.bz2 |
Merge: Tweak programming faq examples so that it (mostly) passes doctest.
-rw-r--r-- | Doc/faq/programming.rst | 37 |
1 files changed, 19 insertions, 18 deletions
diff --git a/Doc/faq/programming.rst b/Doc/faq/programming.rst index 1c5e12f..bf73935 100644 --- a/Doc/faq/programming.rst +++ b/Doc/faq/programming.rst @@ -214,9 +214,9 @@ Why do lambdas defined in a loop with different values all return the same resul Assume you use a for loop to define a few different lambdas (or even plain functions), e.g.:: - squares = [] - for x in range(5): - squares.append(lambda: x**2) + >>> squares = [] + >>> for x in range(5): + ... squares.append(lambda: x**2) This gives you a list that contains 5 lambdas that calculate ``x**2``. You might expect that, when called, they would return, respectively, ``0``, ``1``, @@ -241,9 +241,9 @@ changing the value of ``x`` and see how the results of the lambdas change:: In order to avoid this, you need to save the values in variables local to the lambdas, so that they don't rely on the value of the global ``x``:: - squares = [] - for x in range(5): - squares.append(lambda n=x: n**2) + >>> squares = [] + >>> for x in range(5): + ... squares.append(lambda n=x: n**2) Here, ``n=x`` creates a new variable ``n`` local to the lambda and computed when the lambda is defined so that it has the same value that ``x`` had at @@ -592,11 +592,11 @@ Comma is not an operator in Python. Consider this session:: Since the comma is not an operator, but a separator between expressions the above is evaluated as if you had entered:: - >>> ("a" in "b"), "a" + ("a" in "b"), "a" not:: - >>> "a" in ("b", "a") + "a" in ("b", "a") The same is true of the various assignment operators (``=``, ``+=`` etc). They are not truly operators but syntactic delimiters in assignment statements. @@ -744,6 +744,7 @@ it from. However, if you need an object with the ability to modify in-place unicode data, try using a :class:`io.StringIO` object or the :mod:`array` module:: + >>> import io >>> s = "Hello, world" >>> sio = io.StringIO(s) >>> sio.getvalue() @@ -761,7 +762,7 @@ module:: array('u', 'Hello, world') >>> a[0] = 'y' >>> print(a) - array('u', 'yello world') + array('u', 'yello, world') >>> a.tounicode() 'yello, world' @@ -1060,7 +1061,7 @@ How do I create a multidimensional list? You probably tried to make a multidimensional array like this:: - A = [[None] * 2] * 3 + >>> A = [[None] * 2] * 3 This looks correct if you print it:: @@ -1615,13 +1616,13 @@ file is automatic if you're importing a module and Python has the ability (permissions, free space, etc...) to write the compiled module back to the directory. -Running Python on a top level script is not considered an import and no ``.pyc`` -will be created. For example, if you have a top-level module ``abc.py`` that -imports another module ``xyz.py``, when you run abc, ``xyz.pyc`` will be created -since xyz is imported, but no ``abc.pyc`` file will be created since ``abc.py`` -isn't being imported. +Running Python on a top level script is not considered an import and no +``.pyc`` will be created. For example, if you have a top-level module +``foo.py`` that imports another module ``xyz.py``, when you run ``foo``, +``xyz.pyc`` will be created since ``xyz`` is imported, but no ``foo.pyc`` file +will be created since ``foo.py`` isn't being imported. -If you need to create abc.pyc -- that is, to create a .pyc file for a module +If you need to create ``foo.pyc`` -- that is, to create a ``.pyc`` file for a module that is not imported -- you can, using the :mod:`py_compile` and :mod:`compileall` modules. @@ -1629,9 +1630,9 @@ The :mod:`py_compile` module can manually compile any module. One way is to use the ``compile()`` function in that module interactively:: >>> import py_compile - >>> py_compile.compile('abc.py') + >>> py_compile.compile('foo.py') # doctest: +SKIP -This will write the ``.pyc`` to the same location as ``abc.py`` (or you can +This will write the ``.pyc`` to the same location as ``foo.py`` (or you can override that with the optional parameter ``cfile``). You can also automatically compile all files in a directory or directories using |