python - Variables defined inside if or for statements -


what happens variables assigned first time (defined) inside if statement or for loop if long time passed when code run. there sort of garbage collection may result in not defined variable exception. example:

if true:    a=1 else:    a=3 # long time passed , other codes run # . # . # . print (a)

i encountered error in code suspect reason. documented somewhere in official python documentation ?

in python, if define variable within if statement, continue exist after if statement concludes. scopes defined class, def, or global scope; if you're in function , define variable inside if, example, variable exist until function done executing.

be careful, however, of defining variables in code this:

if x == true:   = 1 else:   print "not true"

if have code this, , x ends being false, a not defined. later calls a throw exception result. make sure rid of potential problems of sort.


Comments

Post a Comment

Popular posts from this blog

javascript - Jquery show_hide, what to add in order to make the page scroll to the bottom of the hidden field once button is clicked -

i have button on website when clicked, reveals map. button can seen when page first loads up, when clicked, section holding map slides open , goes out of screen since page loads @ top (normal). want page scroll down bottom of div select when button pushed, if map out of screen. if page scrolled down, , clicks show map button, don't want page jump bottom of map. i tried figure out myself, no luck. seasoned jquery coders able give me guidance? many thanks! map = mapdiv.gmap3("get"); infobox = new infobox({ pixeloffset: new google.maps.size(-220, -310), closeboxurl: '', enableeventpropagation: true }); mapdiv.delegate('.infobox .close','click',function () { infobox.close(); }); jquery(".slidingdiv").hide(); jquery(".show_hide").show(); jquery('.show_hide').click(function(){ lastcenter=map.getcenter(); jquery(".slidingdiv&quo
Read more

javascript - Highcharts multi-color line -

Image
i looking create highchart multi-colored line. if goes down under value, become red, , when comes on value, become green . here picture example: or maybe highcharts have other charts models differentiate high or low level color? you can achieve coloring using lineargradient coloring: color: { lineargradient: { x1: 0, x2: 0, y1: 0, y2: 1 }, stops: [ [0, 'red'], [0.25, 'yellow'], [0.50, 'green'], [0.75, 'yellow'], [1, 'red'] ] } here 0 in stops relates minimum value of series , 1 maximum value, , in between percentages between values. if find percentages according values prior creating chart use correct stops values make relate specific values in data (at least approximately). see this jsfiddle example .
Read more

javascript - Enter key does not work in search box -

tried search guys sorry. input in search box doesnt work (or search) when hit enter when user clicks search button. doing wrong? here code. thanks. <script type="text/javascript"> $(document).ready(function() { $("#submit").click(function() { var url = "http://asla.org/awardssearch.html"; url += "?s=" + $('#googlecse').val(); window.location = url; }); $('#googlecse').keydown(function(event) { if (event.keycode == '13') { $("#submit").click(); } else { //do nothing :) } }); }); </script> <form class="navbar-form navbar-right" role="search"> <div class="search"> <input id="googlecse" type="text" onblur="if(this.value=='')this.value=this.defaultvalue;" onfocus="if(this.value==this.defaultvalue)t
Read more