djsmith42

This is a sprinkler system with zones and waterings.

A zone is an area that can be watered. It has an ID.

A watering is a scheduled event that consists of an ordered list of zones and how long to water them (durations). Duplicate zones are allowed.

So the API returns data like this:

```
GET /watering/123456

djsmith42

/*
 * Your challenge: Find the bug in this code.
 *
 * The symptom: When I click "Remove" on "Bob", "Fred" disappears. Why?
 *
 * Hint: It's not a syntax error, and there are no console warnings.
 */

class MyComponent extends React.Component {
  constructor() {

djsmith42

function getCurrentUser(callback) {
    $http.get("/api/users/self/").then(function(user) {
        callback(user);
    });
});

function getCurrentUser() {
   var deferred = $q.defer();
   $http.get("/api/users/self/").then(function(user) {
       deferred.resolve(user);

djsmith42

function counter() {
   var n = 0;
   return function() {
      n++;
      return n;
   }
}

c = counter();
c(); // ouputs 1

djsmith42

void my_function() {
   char *data = malloc(1024);
   return; // oops! memory leak
}

djsmith42

scale 562949953421312
bad at 1125899906842624 0x4000000000000 0b100000000000000000000000000000000000000000000000000

scale 281474976710656
bad at 562949953421312 0x2000000000000 0b10000000000000000000000000000000000000000000000000

scale 140737488355328
bad at 281474976710656 0x1000000000000 0b1000000000000000000000000000000000000000000000000

scale 70368744177664

djsmith42

import itertools
for a, b, c, d, e, f in itertools.product(range(1, 10), range(1, 10), range(1, 10), range(1, 10), range(1, 10), range(1, 10)):
    if (a + b + c == 18 and
        d + e + f == 18 and
        a + d == b + e and
        b + e == c + f and
        int(str(e) + str(f)) in [16, 25, 36, 49, 64, 81] and
        len(set([a, b, c, d, e, f])) == 6):
        print a, b, c, d, e, f

djsmith42

print "You can see this"
with suppress_stdout():
    print "You cannot see this"
print "And you can see this again"

djsmith42

from contextlib import contextmanager
import sys, os

@contextmanager
def suppress_stdout():
    with open(os.devnull, "w") as devnull:
        old_stdout = sys.stdout
        sys.stdout = devnull
        try:  
            yield

djsmith42

>>> do_something.func_defaults = ([42],)
>>> do_something()
[42, 'some item']
>>>