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various typos [thanks G.P.]

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Mark Pilgrim
2009-06-01 12:19:43 -07:00
parent 992b4bd18b
commit bca614e2be
6 changed files with 104 additions and 30 deletions
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your-first-python-program.html
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@@ -81,7 +81,7 @@ if __name__ == "__main__":
<blockquote class=note>
<p><span>&#x261E;</span>In some languages, functions (that return a value) start with <code>function</code>, and subroutines (that do not return a value) start with <code>sub</code>. There are no subroutines in Python. Everything is a function, all functions return a value (even if it&#8217;s <code>None</code>), and all functions start with <code>def</code>.
</blockquote>
<p>The <code>approximate_size</code> function takes the two arguments &mdash; <var>size</var> and <var>a_kilobyte_is_1024_bytes</var> &mdash; but neither argument specifies a datatype. In Python, variables are never explicitly typed. Python figures out what type a variable is and keeps track of it internally.
<p>The <code>approximate_size()</code> function takes the two arguments &mdash; <var>size</var> and <var>a_kilobyte_is_1024_bytes</var> &mdash; but neither argument specifies a datatype. In Python, variables are never explicitly typed. Python figures out what type a variable is and keeps track of it internally.
<blockquote class="note compare java">
<p><span>&#x261E;</span>In Java and other statically-typed languages, you must specify the datatype of the function return value and each function argument. In Python, you never explicitly specify the datatype of anything. Based on what value you assign, Python keeps track of the datatype internally.
</blockquote>
@@ -90,7 +90,7 @@ if __name__ == "__main__":
<p>Python allows function arguments to have default values; if the function is called without the argument, the argument gets its default value. Futhermore, arguments can be specified in any order by using named arguments.
<p>Let&#8217;s take another look at that <code>approximate_size</code> function declaration:
<p>Let&#8217;s take another look at that <code>approximate_size()</code> function declaration:
<pre><code>def approximate_size(size, a_kilobyte_is_1024_bytes=True):</code></pre>
@@ -136,7 +136,7 @@ SyntaxError: non-keyword arg after keyword arg</samp></pre>
<h2 id=readability>Writing Readable Code</h2>
<p>I won&#8217;t bore you with a long finger-wagging speech about the importance of documenting your code. Just know that code is written once but read many times, and the most important audience for your code is yourself, six months after writing it (i.e. after you&#8217;ve forgotten everything but need to fix something). Python makes it easy to write readable code, so take advantage of it. You&#8217;ll thank me in six months.
<h3 id=docstrings>Documentation Strings</h3>
<p>You can document a Python function by giving it a documentation string (<code>docstring</code> for short). In this program, the <code>approximate_size</code> function has a <code>docstring</code>:
<p>You can document a Python function by giving it a documentation string (<code>docstring</code> for short). In this program, the <code>approximate_size()</code> function has a <code>docstring</code>:
<pre><code>def approximate_size(size, a_kilobyte_is_1024_bytes=True):
"""Convert a file size to human-readable form.