Popular recipes tagged "meta:score=2"http://code.activestate.com/recipes/tags/meta:score=2/2017-07-17T05:53:45-07:00ActiveState Code RecipesUno (Text-Based) (Python) 2017-07-15T00:46:59-07:00Brandon Martinhttp://code.activestate.com/recipes/users/4194238/http://code.activestate.com/recipes/580811-uno-text-based/ <p style="color: grey"> Python recipe 580811 by <a href="/recipes/users/4194238/">Brandon Martin</a> (<a href="/recipes/tags/artificial_intelligence/">artificial_intelligence</a>, <a href="/recipes/tags/cards/">cards</a>, <a href="/recipes/tags/game/">game</a>, <a href="/recipes/tags/text_game/">text_game</a>, <a href="/recipes/tags/uno/">uno</a>). </p> <p>A text based recreation of the classic card game featuring functional AIs to play with. Some rules have been modified. User interface is text based, non-curses, using only simple python commands to draw it. </p> Insert a Text Box in a PDF page (fitz / PyMuPDF) (Python) 2017-06-29T22:54:25-07:00Jorj X. McKiehttp://code.activestate.com/recipes/users/4193772/http://code.activestate.com/recipes/580809-insert-a-text-box-in-a-pdf-page-fitz-pymupdf/ <p style="color: grey"> Python recipe 580809 by <a href="/recipes/users/4193772/">Jorj X. McKie</a> (<a href="/recipes/tags/fitz/">fitz</a>, <a href="/recipes/tags/mupdf/">mupdf</a>, <a href="/recipes/tags/pdf/">pdf</a>, <a href="/recipes/tags/textbox/">textbox</a>). </p> <p>This method inserts text into a predefined rectangular area of a (new or existing) PDF page. Words are distributed across the available space, put on new lines when required etc. Line breaks and tab characters are respected / resolved. Text can be aligned in the box (left, center, right) and fonts can be freely chosen. The method returns a float indicating how vertical space is left over after filling the area.</p> Frame with border color for Tkinter (Python) 2017-04-17T11:25:02-07:00Miguel Martínez Lópezhttp://code.activestate.com/recipes/users/4189907/http://code.activestate.com/recipes/580735-frame-with-border-color-for-tkinter/ <p style="color: grey"> Python recipe 580735 by <a href="/recipes/users/4189907/">Miguel Martínez López</a> (<a href="/recipes/tags/border/">border</a>, <a href="/recipes/tags/color/">color</a>, <a href="/recipes/tags/frame/">frame</a>, <a href="/recipes/tags/tkinter/">tkinter</a>). </p> <p>This trick show how to add a border color to frame. These are the important configurations:</p> <pre class="prettyprint"><code> highlightbackground="your border color here" highlightcolor="your border color here" highlightthickness="the border width" bd= 0 </code></pre> Inserting Images on PDF Pages (Python) 2017-05-17T21:10:26-07:00Jorj X. McKiehttp://code.activestate.com/recipes/users/4193772/http://code.activestate.com/recipes/580803-inserting-images-on-pdf-pages/ <p style="color: grey"> Python recipe 580803 by <a href="/recipes/users/4193772/">Jorj X. McKie</a> (<a href="/recipes/tags/fitz/">fitz</a>, <a href="/recipes/tags/mupdf/">mupdf</a>, <a href="/recipes/tags/pdf/">pdf</a>, <a href="/recipes/tags/pymupdf/">pymupdf</a>). </p> <p>Version 1.11.0 of PyMuPDF allows putting an image on an existing PDF page. The following example puts the same image on every page of a given PDF - like a thumbnail.</p> Convert Microsot Excel (XLSX) to PDF with Python and xtopdf (Python) 2015-11-22T22:15:25-08:00Vasudev Ramhttp://code.activestate.com/recipes/users/4173351/http://code.activestate.com/recipes/579128-convert-microsot-excel-xlsx-to-pdf-with-python-and/ <p style="color: grey"> Python recipe 579128 by <a href="/recipes/users/4173351/">Vasudev Ram</a> (<a href="/recipes/tags/excel/">excel</a>, <a href="/recipes/tags/formats/">formats</a>, <a href="/recipes/tags/openpyxl/">openpyxl</a>, <a href="/recipes/tags/pdf/">pdf</a>, <a href="/recipes/tags/python/">python</a>, <a href="/recipes/tags/xlsx/">xlsx</a>, <a href="/recipes/tags/xtopdf/">xtopdf</a>). </p> <p>This recipe shows how the basics of to convert the text data in a Microsoft Excel file (XLSX format) to PDF (Portable Document Format). It uses openpyxl to read the XLSX file and xtopdf to generate the PDF file.</p> Implementing function-based callbacks in Python (Python) 2017-04-19T18:03:11-07:00Vasudev Ramhttp://code.activestate.com/recipes/users/4173351/http://code.activestate.com/recipes/580787-implementing-function-based-callbacks-in-python/ <p style="color: grey"> Python recipe 580787 by <a href="/recipes/users/4173351/">Vasudev Ram</a> (<a href="/recipes/tags/callback/">callback</a>, <a href="/recipes/tags/function/">function</a>, <a href="/recipes/tags/functions/">functions</a>, <a href="/recipes/tags/python/">python</a>, <a href="/recipes/tags/techniques/">techniques</a>). </p> <p>This recipe shows a simple way of implementing callbacks in Python. There are a few ways this can be done. The way shown here uses a simple function-based approach.</p> <p>In a nutshell, a callback can be informally described like this: function <strong>a</strong> calls function <strong>b</strong>, and wants to make <strong>b</strong> run a specific independent chunk of code at some point during <strong>b</strong>'s execution. We want to be able to vary which chunk of code gets called in different calls to <strong>b</strong>, so it cannot be hard-coded inside <strong>b</strong>. So function <strong>a</strong> passes another function, <strong>c</strong>, to <strong>b</strong>, as one argument, and <strong>b</strong> uses that parameter <strong>c</strong> to call the functionality that <strong>a</strong> wants <strong>b</strong> to call. (Function <strong>b</strong> may pass some parameters to the function represented by <strong>c</strong>, when it calls it. These could be either internally generated, passed from <strong>a</strong>, or a combination of both). So, by changing the value of the function <strong>c</strong> that gets passed to <strong>b</strong> (on different calls to <strong>b</strong>), <strong>a</strong> can change what chunk of code <strong>b</strong> calls.</p> <p>More details and full code, description and output here:</p> <p><a href="https://jugad2.blogspot.in/2017/04/implementing-and-using-callbacks-in.html" rel="nofollow">https://jugad2.blogspot.in/2017/04/implementing-and-using-callbacks-in.html</a></p> Implementing class-based callbacks in Python (Python) 2017-04-20T23:34:50-07:00Vasudev Ramhttp://code.activestate.com/recipes/users/4173351/http://code.activestate.com/recipes/580788-implementing-class-based-callbacks-in-python/ <p style="color: grey"> Python recipe 580788 by <a href="/recipes/users/4173351/">Vasudev Ram</a> (<a href="/recipes/tags/callbacks/">callbacks</a>, <a href="/recipes/tags/classes/">classes</a>, <a href="/recipes/tags/functions/">functions</a>, <a href="/recipes/tags/methods/">methods</a>, <a href="/recipes/tags/objects/">objects</a>, <a href="/recipes/tags/programming/">programming</a>, <a href="/recipes/tags/python/">python</a>). </p> <p>This is a follow-on to this recently posted recipe:</p> <p>Implementing function-based callbacks in Python: <a href="https://code.activestate.com/recipes/580787-implementing-function-based-callbacks-in-python/?in=user-4173351" rel="nofollow">https://code.activestate.com/recipes/580787-implementing-function-based-callbacks-in-python/?in=user-4173351</a></p> <p>This new recipe shows how to create and use callbacks in Python, using classes with methods, instead of plain functions, as was done in the recipe linked above. All other points such as reasons and benefits for using callbacks, are more or less the same as mentioned in the previous recipe, except that class instances can carry state around, so to that extent, the two approaches are different.</p> <p><a href="https://jugad2.blogspot.in/2017/04/python-callbacks-using-classes-and.html" rel="nofollow">https://jugad2.blogspot.in/2017/04/python-callbacks-using-classes-and.html</a></p> Create Calendars on PDF with a few lines (Python) 2017-06-13T10:57:34-07:00Jorj X. McKiehttp://code.activestate.com/recipes/users/4193772/http://code.activestate.com/recipes/580805-create-calendars-on-pdf-with-a-few-lines/ <p style="color: grey"> Python recipe 580805 by <a href="/recipes/users/4193772/">Jorj X. McKie</a> (<a href="/recipes/tags/calendar/">calendar</a>, <a href="/recipes/tags/fitz/">fitz</a>, <a href="/recipes/tags/mupdf/">mupdf</a>, <a href="/recipes/tags/pdf/">pdf</a>, <a href="/recipes/tags/pymupdf/">pymupdf</a>). Revision 2. </p> <p>PyMuPDF (fitz) provides easy to use ways to create PDF documents out of simple texts.</p> <p>An example is the text output of Python's calendar module. Here we take a starting year as script parameter and output a 3-page (A4 landscape) document with calendars for this and the following two years - in less than 20 lines of code.</p> How to create a simple PDF Pie Chart using fitz / PyMuPDF (Python) 2017-07-10T16:07:51-07:00Jorj X. McKiehttp://code.activestate.com/recipes/users/4193772/http://code.activestate.com/recipes/580810-how-to-create-a-simple-pdf-pie-chart-using-fitz-py/ <p style="color: grey"> Python recipe 580810 by <a href="/recipes/users/4193772/">Jorj X. McKie</a> (<a href="/recipes/tags/fitz/">fitz</a>, <a href="/recipes/tags/pdf_generation/">pdf_generation</a>). </p> <p>PyMuPDF now supports drawing pie charts on a PDF page.</p> <p>Important parameters for the function are center of the circle, one of the two arc's end points and the angle of the circular sector. The function will draw the pie piece (in a variety of options) and return the arc's calculated other end point for any subsequent processing.</p> <p>This example creates a chart of the parliament seat distribution for political parties in the current German Bundestag.</p> Inserting pages into a PDF with PyMuPDF (Python) 2017-05-17T21:15:26-07:00Jorj X. McKiehttp://code.activestate.com/recipes/users/4193772/http://code.activestate.com/recipes/580802-inserting-pages-into-a-pdf-with-pymupdf/ <p style="color: grey"> Python recipe 580802 by <a href="/recipes/users/4193772/">Jorj X. McKie</a> (<a href="/recipes/tags/fitz/">fitz</a>, <a href="/recipes/tags/mupdf/">mupdf</a>, <a href="/recipes/tags/pdf/">pdf</a>, <a href="/recipes/tags/text_conversion/">text_conversion</a>). Revision 2. </p> <p>Version 1.11.0 of PyMuPDF allows creating new PDF pages, as well as inserting images into existing pages.</p> <p>Here is a script that converts any textfile into a PDF.</p> Shoelace Formula for polygonal area (Python) 2017-07-17T05:53:45-07:00Paddy McCarthyhttp://code.activestate.com/recipes/users/398009/http://code.activestate.com/recipes/580812-shoelace-formula-for-polygonal-area/ <p style="color: grey"> Python recipe 580812 by <a href="/recipes/users/398009/">Paddy McCarthy</a> (<a href="/recipes/tags/2d/">2d</a>, <a href="/recipes/tags/area/">area</a>). </p> <p>Copied, by author from "Paddy3118 Go deh!: Python investigation of the Shoelace Formula for polygonal area <a href="http://paddy3118.blogspot.com/2017/07/python-investigation-of-shoelace.html#ixzz4n43Dqhaa" rel="nofollow">http://paddy3118.blogspot.com/2017/07/python-investigation-of-shoelace.html#ixzz4n43Dqhaa</a> " Where there is more meat on the bone (under a different license though).</p> Simple multicolumn listbox for tkinter (Python) 2017-05-02T22:27:15-07:00Miguel Martínez Lópezhttp://code.activestate.com/recipes/users/4189907/http://code.activestate.com/recipes/580794-simple-multicolumn-listbox-for-tkinter/ <p style="color: grey"> Python recipe 580794 by <a href="/recipes/users/4189907/">Miguel Martínez López</a> (<a href="/recipes/tags/listbox/">listbox</a>, <a href="/recipes/tags/multicolumn/">multicolumn</a>, <a href="/recipes/tags/table/">table</a>, <a href="/recipes/tags/tkinter/">tkinter</a>). </p> <p>This recipe makes easy to work a treeview widget like a table.</p> <p>It has several options for styling:</p> <ul> <li>heading_anchor</li> <li>heading_font</li> <li>heading_background</li> <li>heading_foreground</li> <li>cell_anchor</li> <li>cell_background</li> <li>cell_foreground</li> <li>cell_font</li> <li>cell_pady</li> <li>height</li> <li>padding</li> <li>adjust_heading_to_content</li> <li>stripped_rows</li> <li>headers</li> <li>selection_background</li> <li>selection_foreground</li> <li>field_background</li> </ul> <p>The "command" parameter is a callback and its called each time a row is selected.</p> How to Create a PDF with a Caustic Drawing (Python) 2017-06-18T17:43:47-07:00Jorj X. McKiehttp://code.activestate.com/recipes/users/4193772/http://code.activestate.com/recipes/580806-how-to-create-a-pdf-with-a-caustic-drawing/ <p style="color: grey"> Python recipe 580806 by <a href="/recipes/users/4193772/">Jorj X. McKie</a> (<a href="/recipes/tags/fitz/">fitz</a>, <a href="/recipes/tags/mupdf/">mupdf</a>, <a href="/recipes/tags/pdf/">pdf</a>, <a href="/recipes/tags/pymupdf/">pymupdf</a>). </p> <p>Just a little demo on how to create simple drawings with PyMuPDF.</p> <p>This script simulates what you see looking into your coffee mug, early in the morning after a long night of programming ...</p> Tkinter frame with gradient (Python) 2017-03-11T03:43:56-08:00Miguel Martínez Lópezhttp://code.activestate.com/recipes/users/4189907/http://code.activestate.com/recipes/580761-tkinter-frame-with-gradient/ <p style="color: grey"> Python recipe 580761 by <a href="/recipes/users/4189907/">Miguel Martínez López</a> (<a href="/recipes/tags/canvas/">canvas</a>, <a href="/recipes/tags/frame/">frame</a>, <a href="/recipes/tags/gradient/">gradient</a>, <a href="/recipes/tags/tkinter/">tkinter</a>). Revision 4. </p> <p>Frame with linear gradient using PIL. </p> <p>It's also possible to make the same trick using tkinter PhotoImage.</p> <p><a href="http://stackoverflow.com/questions/10417524/why-is-photoimage-put-slow" rel="nofollow">http://stackoverflow.com/questions/10417524/why-is-photoimage-put-slow</a></p> <p>But PIL is more efficient:</p> <p><a href="https://groups.google.com/forum/#%21topic/comp.lang.python/nQ6YO-dTz10" rel="nofollow">https://groups.google.com/forum/#!topic/comp.lang.python/nQ6YO-dTz10</a></p> <p>Possible values for <strong>orient</strong> are: <em>VERTICAL</em>, <em>HORIZONTAL</em>. If <strong>orient</strong> is "vertical", then width is mandatory. If <strong>orient</strong> is "horizontal", then height is mandatory. If <strong>steps</strong> is <em>None</em>, then the gradient is composed of adjacent lines.</p> <p>One possible practical application of gradient frames are tool bars. Gradient guives a visual clue of when an area starts and when an area finish. </p> Tkinter search box (Python) 2017-04-08T12:27:36-07:00Miguel Martínez Lópezhttp://code.activestate.com/recipes/users/4189907/http://code.activestate.com/recipes/580773-tkinter-search-box/ <p style="color: grey"> Python recipe 580773 by <a href="/recipes/users/4189907/">Miguel Martínez López</a> (<a href="/recipes/tags/entry/">entry</a>, <a href="/recipes/tags/search/">search</a>, <a href="/recipes/tags/searchbox/">searchbox</a>, <a href="/recipes/tags/tkinter/">tkinter</a>). Revision 9. </p> <p>Instead of using two colors for active background and normal background, I use only one color and opacity parameter.</p> <p>I trigger the feeling of a button using different colors when the mouse is and isn't over. Many modern HTML search boxes uses the same approach.</p> <p>Command function receives text of entry box when button is pressed.</p> Tkinter Link or Hyperlink Button (Python) 2017-04-07T11:51:26-07:00Miguel Martínez Lópezhttp://code.activestate.com/recipes/users/4189907/http://code.activestate.com/recipes/580774-tkinter-link-or-hyperlink-button/ <p style="color: grey"> Python recipe 580774 by <a href="/recipes/users/4189907/">Miguel Martínez López</a> (<a href="/recipes/tags/button/">button</a>, <a href="/recipes/tags/hyperlink/">hyperlink</a>, <a href="/recipes/tags/link/">link</a>, <a href="/recipes/tags/tkinter/">tkinter</a>, <a href="/recipes/tags/webbrowser/">webbrowser</a>). Revision 6. </p> <p>If a background is not provided, the widget gets the background color from its container. The link button has two states: normal and visited. When the link is clicked, the state change to visited. When the link is clicked the action command is called. By default the text of the link has an underline. There is several options for customization.</p> <p>I also added this megawidget to my "Metro UI Tkinter" recipe:</p> <p><a href="https://code.activestate.com/recipes/580729-metro-ui-tkinter" rel="nofollow">https://code.activestate.com/recipes/580729-metro-ui-tkinter</a></p> Variable Abbreviations (Python) 2017-06-22T11:57:20-07:00Alfehttp://code.activestate.com/recipes/users/4182236/http://code.activestate.com/recipes/580807-variable-abbreviations/ <p style="color: grey"> Python recipe 580807 by <a href="/recipes/users/4182236/">Alfe</a> (<a href="/recipes/tags/abbreviations/">abbreviations</a>, <a href="/recipes/tags/contextmanager/">contextmanager</a>, <a href="/recipes/tags/variables/">variables</a>, <a href="/recipes/tags/with/">with</a>). </p> <p>One sometimes has nice long speaking names vor variables, maybe things like <code>buildingList[foundIndex].height</code>, but would like to address these in a shorter fashion to be used within a formula or similar where lots of longs names tend to confuse any reader trying to understand the formula. Physicists use one-letter names for a reason.</p> <p>For this I wrote a small context provider which allows using short names instead of long ones:</p> <pre class="prettyprint"><code>with Abbr(h=buildingList[foundIndex].height, g=gravitationalConstant): fallTime = sqrt(2 * h / g) endSpeed = sqrt(2 * h * g) print("Fall time:", fallTime) print("End speed:", endSpeed) </code></pre> <p>For longer formulas this can reduce ugly multi-line expressions to clearly readable one-liners.</p> <p>One could use this:</p> <pre class="prettyprint"><code>h = buildingList[foundIndex].height g = gravitationalConstant fallTime = sqrt(2 * h / g) endSpeed = sqrt(2 * h * g) del g, h print("Fall time:", fallTime) print("End speed:", endSpeed) </code></pre> <p>to achieve the same result, but</p> <ul> <li>it would not look as clean and</li> <li>the context provider solves the typical issues like cleanup on exception etc.</li> </ul> <p>Just using local variables without cleanup (like above without the <code>del</code> statement) also is an option of course, but that would clutter the variable name space unnecessarily.</p> <p>CAVEATS: The implementation of <code>Abbr()</code> is a hack. If used as intended and described here, it should work just fine, though. But the hackish nature forces me to mention some things: Since at compile time the compiler decides that the <code>h</code> and <code>g</code> in the example must be global variables (because they aren't assigned in the function), it produces byte code accessing global variables. The context provider changes the global variable structure to fill the needs. (Overridden already existing global variables of the same name get restored properly at context exit.) This means some things:</p> <ul> <li>One cannot have a local variable of the same name in the frame surrounding the context manager.</li> <li>Existing global variables are changed during the time of the context manager; so using names like <code>sys</code> or <code>os</code> for abbreviations might be a bad idea due to side-effects.</li> </ul> Guard against an exception in the wrong place (Python) 2017-06-25T17:17:43-07:00Steven D'Apranohttp://code.activestate.com/recipes/users/4172944/http://code.activestate.com/recipes/580808-guard-against-an-exception-in-the-wrong-place/ <p style="color: grey"> Python recipe 580808 by <a href="/recipes/users/4172944/">Steven D'Aprano</a> (<a href="/recipes/tags/context/">context</a>, <a href="/recipes/tags/exception/">exception</a>, <a href="/recipes/tags/guard/">guard</a>, <a href="/recipes/tags/manager/">manager</a>). Revision 2. </p> <p>Sometimes exception handling can obscure bugs unless you guard against a particular exception occurring in a certain place. One example is that <a href="https://www.python.org/dev/peps/pep-0479/">accidentally raising <code>StopIteration</code> inside a generator</a> will halt the generator instead of displaying a traceback. That was solved by PEP 479, which automatically has such <code>StopIteration</code> exceptions change to <code>RuntimeError</code>. See the discussion below for further examples.</p> <p>Here is a class which can be used as either a decorator or context manager for guarding against the given exceptions. It takes an exception (or a tuple of exceptions) as argument, and if the wrapped code raises that exception, it is re-raised as another exception type (by default <code>RuntimeError</code>).</p> <p>For example:</p> <pre class="prettyprint"><code>try: with exception_guard(ZeroDivisionError): 1/0 # raises ZeroDivisionError except RuntimeError: print ('ZeroDivisionError replaced by RuntimeError') @exception_guard(KeyError) def demo(): return {}['key'] # raises KeyError try: demo() except RuntimeError: print ('KeyError replaced by RuntimeError') </code></pre> How to Maintain PDF Links with fitz / PyMuPDF (Python) 2017-03-22T13:12:25-07:00Jorj X. McKiehttp://code.activestate.com/recipes/users/4193772/http://code.activestate.com/recipes/580765-how-to-maintain-pdf-links-with-fitz-pymupdf/ <p style="color: grey"> Python recipe 580765 by <a href="/recipes/users/4193772/">Jorj X. McKie</a> (<a href="/recipes/tags/fitz/">fitz</a>, <a href="/recipes/tags/link/">link</a>, <a href="/recipes/tags/mupdf/">mupdf</a>, <a href="/recipes/tags/pdf/">pdf</a>). </p> <p>This REPL script example displays, updates, inserts and deletes links on a PDF page.</p> Unit Testing Nested Functions (Python) 2016-11-10T10:23:11-08:00Alfehttp://code.activestate.com/recipes/users/4182236/http://code.activestate.com/recipes/580716-unit-testing-nested-functions/ <p style="color: grey"> Python recipe 580716 by <a href="/recipes/users/4182236/">Alfe</a> (<a href="/recipes/tags/introspection/">introspection</a>, <a href="/recipes/tags/nested/">nested</a>, <a href="/recipes/tags/unittests/">unittests</a>). Revision 3. </p> <p>Python allows the declaration of nested functions. These are typically hard to unit test because using just the normal ways of calling they cannot be called from outside their surrounding function. So they cannot be considered a clearly separated unit and thus cannot be unit tested.</p> <p>This is a drawback of using them, so many developers (especially the ones deep into test driven development who strive to have a high unit test coverage) tend to avoid them in favor for standalone functions which can be called from the unit tests without any hassle.</p> <p>But not all solutions with nested functions can be written as elegant with standalone functions. Nested functions are powerful insofar that they can access the local variables of the surrounding function without any need to pass them into the nested function, thus the code can in many cases stay neat and tidy while using a standalone function instead might raise the need to pass the complete context in form of a bunch of parameters. Also, using nested functions makes their local usage clear to any reader and keeps the name space tight.</p> <p>But at least in the standard CPython (i. e. not necessarily in Jython, etc.) the implementation of functions (and methods) allows to find the nested function's code, wrap it properly to give it its needed context and then call it from the outside. I wrote a small module which helps doing exactly this.</p>