python equivalent to java guava Preconditions -


does python have equivalent java preconditions library. e.g.

in java, can check parameters this:

public void dummymethod(cat a, dog b) {    preconditions.checknotnull(a, "a can not null.");    preconditions.checknotnull(b, "b can not null.");    /**    logic    **/    }

if or b null, java throws runtime exception, how python, what's best practice here python?

while can use assert verify conditions, best practice in python document behaviour of function, , let fail if preconditions not met.

for example, if reading file, like:

def read_from_file(filename):     f = open(filename, 'ru') # allow ioerror if file doesn't exist / invalid permissions

rather testing failure cases first.


Comments

Post a Comment

Popular posts from this blog

php - cannot display multiple markers in google maps v3 from traceroute result -

i'm newbie in php mysql , google maps v3. have problems in google maps v3. made traceroute web based , map traceroute's result in google maps v3 final project of college education. have try many tutorials didn't work. have tried tutorials in forum nothing worked. problem cannot display multiple markers got location data database. maybe because i'm newbie , not know how do. confuse looping show markers. here code <?php error_reporting(e_all ^ (e_notice)); ini_set('max_execution_time', 360); $enable_log_user = false; global $ip, $host_name, $host_ip; $host = @$_post['host']; $trace = @$_post['trace']; $self = $_server['php_self']; include("phpsqlajax_dbinfo.php"); $connection = mysql_connect ('127.0.0.1', $username, $password); if (!$connection) { die('not connected : ' . mysql_error());} $db_selected = mysql_select_db($database, $connection); if (!$db_selected) { die ('can\'t use db : ...
Read more

c# - DetailsView in ASP.Net - How to add another column on the side/add a control in each row? -

i have detailsview control on page used edit various fields of record, works in respect. i looking way add 1 column (and if works, why not more) right, absolutely read-only, show same fields of record comparison purposes. i aware there no obvious way such thing out of box detailsview . have looked other controls (transposed gridview , recommended formview , listview ), nothing satisfies. have special data binding setup using detailsview , can't out of without losing features. anyone on how "hack in" additional columns (for display only) on detailsview ? the solution have now, use second detailsview , visible set false in aspx. in code, make sure databind hidden detailsview hosts data third column first, initial detailsview named itemdetails . and in item created event, pass third column html rendering of hidden controls (in last code block) : protected void itemdetails_itemcreated(object sender, eventargs e) { if (dataite...
Read more

javascript - firefox memory leak -

i have following script (i use raphaeljs also) draws circle, waits 1 second, draws circle again, etc (you can copy paste - functional, need include raphael raphaeljs.com): <div id="holder"> </div> <script src="raphael.js" type="text/javascript"></script> <script> var paper = raphael(10, 50, 320, 200); var rad = math.pi / 180; var finangle = 0; function sector(cx, cy, r, startangle, endangle, params) { var x1 = cx + r * math.cos(-startangle * rad), x2 = cx + r * math.cos(-endangle * rad), y1 = cy + r * math.sin(-startangle * rad), y2 = cy + r * math.sin(-endangle * rad); return ["m", cx, cy, "l", x1, y1, "a", r, r, 0, +(endangle - startangle > 180), 0, x2, y2]; } var path = sector(100,100,50,0,180); var arc = paper.path(path); function draw() { path = sector(100,100,50,0,finangle); ...
Read more