kennethreitz/dive-into-python3
1
0
Fork 0
mirror of https://github.com/kennethreitz/dive-into-python3.git synced 2026-06-05 23:10:17 +00:00
Code Issues Packages Projects Releases Wiki Activity

validation

Browse Source
This commit is contained in:
Mark Pilgrim
2009-08-05 22:30:33 -07:00
parent ea656b4d30
commit 6b48cf96c3
1 changed files with 6 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files
advanced-iterators.html
+6 -6
View File
@@ -51,7 +51,7 @@ import itertools
def solve(puzzle):
words = re.findall('[A-Z]+', puzzle.upper())
unique_characters = set(''.join(words))
assert len(unique_characters) <= 10, 'Too many letters'
assert len(unique_characters) &lt;= 10, 'Too many letters'
first_letters = {word[0] for word in words}
n = len(first_letters)
sorted_characters = ''.join(first_letters) + \
@@ -164,11 +164,11 @@ if __name__ == '__main__':
<a><samp class=p>>>> </samp><kbd class=pp>assert 1 + 1 == 2</kbd> <span class=u>&#x2460;</span></a>
<a><samp class=p>>>> </samp><kbd class=pp>assert 1 + 1 == 3</kbd> <span class=u>&#x2461;</span></a>
<samp class=traceback>Traceback (most recent call last):
File "&lt;stdin>", line 1, in <module>
File "&lt;stdin>", line 1, in &lt;module>
AssertionError</samp>
<a><samp class=p>>>> </samp><kbd class=pp>assert 2 + 2 == 5, "Only for very large values of 2"</kbd> <span class=u>&#x2462;</span></a>
<samp class=traceback>Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "<stdin>", line 1, in &lt;module>
AssertionError: Only for very large values of 2</samp></pre>
<ol>
<li>The <code>assert</code> statement is followed by any valid Python expression. In this case, the expression <code>1 + 1 == 2</code> evaluates to <code>True</code>, so the <code>assert</code> statement does nothing.
@@ -335,7 +335,7 @@ StopIteration</samp>
<p>What does this have to do with the <code>itertools</code> module? I&#8217;m glad you asked.
<pre class=screen>
<p>&hellip;continuing from the previous interactive shell&hellip;
&hellip;continuing from the previous interactive shell&hellip;
<samp class=p>>>> </samp><kbd class=pp>import itertools</kbd>
<a><samp class=p>>>> </samp><kbd class=pp>groups = itertools.groupby(names, len)</kbd> <span class=u>&#x2460;</span></a>
<samp class=p>>>> </samp><kbd class=pp>groups</kbd>
@@ -582,8 +582,8 @@ NameError: name '__import__' is not defined</samp>
<samp class=p>>>> </samp><kbd class=pp>eval("__import__('subprocess').getoutput('rm -rf /')",</kbd>
<a><samp class=p>... </samp><kbd class=pp> {"__builtins__":None}, {})</kbd> <span class=u>&#x2461;</span></a>
<samp class=traceback>Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "<string>", line 1, in <module>
File "&lt;stdin>", line 1, in <module>
File "&lt;string>", line 1, in <module>
NameError: name '__import__' is not defined</samp></pre>
<ol>
<li>To evaluate untrusted expressions safely, you need to define a global namespace dictionary that maps <code>"__builtins__"</code> to <code>None</code>, the Python null value. Internally, the &#8220;built-in&#8221; functions are contained within a pseudo-module called <code>"__builtins__"</code>. This pseudo-module (<i>i.e.</i> the set of built-in functions) is made available to evaluated expressions unless you explicitly override it.