Using D1 with phobos
I have a text entry field, instance of gtk.Entry.Entry,
calling setText("") raises a run time error
Gtk-CRITICAL **: gtk_entry_set_text: assertion `text != NULL' failed
Why? It seems to be a problem with D, I tried this:
string empty = "";
assert (empty != null);
my_entry.setText(empty)
The program terminated as the assertion failed.
How can I work around this?
I don't think D really differentiates between "empty string" and "null string". A cheap workaround would be setText(" ").
[edit] Nevermind that. It's a bug in gtkD. in trunk/src/glib/Str.d (thanks wm4 for finding it), change line 147 to return ""; (remove the .dup).
You should write assert(empty !is null) instead of assert(empty != null)
I used "\0" and it seemed to work,
I don't know if any invisible character got into the text field, but this is based on the assumption that an empty string in C is just \0
Related
I am making an application which rarely uses the terminal for output. So, I found that the logging library was a great way to help debug faulty code as supposed to the print statement.
But, for this code, specifically the .get() statement at the bottom...
def process_variables(self, argument):
data = pd.read_excel(self.url, sheet_name=self.sheet)
data = pd.concat([data.iloc[2:102], data.iloc[107:157]]).reset_index()
fb = data.loc[0:99, :].reset_index()
nfb = data.loc[100:155, :].reset_index()
return {'fb': data.loc[0:99, :].reset_index(),
'nfb': data.loc[100:155, :].reset_index(),
'bi': data.loc[np.where(data['Unnamed: 24'] != ' ')],
'uni': data.loc[np.where(data['Unnamed: 25'] != ' ')],
'fb_bi': fb.loc[np.where(fb['Unnamed: 24'] != ' ')],
'fb_uni': fb.loc[np.where(fb['Unnamed: 25'] != ' ')],
'nfb_bi': nfb.loc[np.where(nfb['Unnamed: 24'] != ' ')],
'nfb_uni': nfb.loc[np.where(nfb['Unnamed: 25'] != ' ')],
}.get(argument, f"{logging.warning(f'{argument} not found in specified variables')}")
...returns this...
output
The output returns the default argument even though the switch-case argument was successful, given that it did return the pandas Data frame.
So how can I make it so it only appears when it wasn't found, as it should if it were just a string and not a logging-string method.
Thank you for your help in advance :)
Python evaluates the arguments for the arguments to a function before it calls the function. That's why your logging function will get called regardless of the result of get(). Another thing is your f-string is probably going to evaluate to "None" every time since logging.warning() doesn't return anything, which doesn't seem like what you intended. You should just handle this with a regular if statement like
variables = {
'fb': data.loc[0:99, :].reset_index(),
...
}
if argument in variables:
return variables[argument]
else:
logging.warning(f'{argument} not found in specified variables')
For instance:
try{
Parser p = Parser();
Expression exp = p.parse(expression);
ContextModel cm = ContextModel();
evaluated = exp.evaluate(EvaluationType.REAL, cm);
result = '$evaluated';
}
catch(e)
{
result = "no";
}
I see a lot of flutter related youtube tutorials simply putting "e" as their argument in the catch. Why do we do this? Does e simply mean any type of error?
No there is no special meaning, e is used as a placeholder. You can actually put any letter or allowed symbol like (_), and it will still represent the exception type incoming when error is thrown.
The parameter of catch is the exception object that is being thrown.
It's just the name of exeption, you can call it "exeption" or "e" . In most cases you`re going to see this written as "e" - short for exeption or error.
while answers_right < 3:
ran_number_1 = random.randint(10, 99)
ran_number_2 = random.randint(10, 99)
solution = ran_number_1 + ran_number_2
print(f"What is {ran_number_1} + {ran_number_2}?")
user_answer = int(input("Your answer: "))
if user_answer == solution:
answers_right += 1
print(f"Correct. You've gotten {answers_right} correct in a row.")
elif user_answer != solution:
answers_right = 0
print(f"Incorrect. The expected answer is {solution}.")
if answers_right == 3:
print("Congratulations! You've mastered addition.")
I want to add an additional if statement in case someone types string and return a message that says "Invalid Response" instead of the Traceback Error.
Use of Exception handling in python may be solve your Problem and you can also generate your own error class for particular condition.
if x < 3:
raise Exception("Sorry, no numbers below 3")
Use of throw and raise keyword you can generate your own error.
for more referencelink here
The correct way to solve this problem is to look at the error type in your traceback, and use a try/except block. It will say something like TypeError: error stuff here or ValueError: error stuff also here.
The way you do a try/except is to:
try:
some_code()
that_might()
produce_an_error()
except some_error_type:
do_stuff()
except_some_other_error_type:
do_other_stuff()
So, to catch a ValueError and a TypeError, you might do:
try:
buggy_code()
except ValueError:
print("Woah, you did something you shouldn't have")
except TypeError:
print("Woah, you did something ELSE you shouldn't have")
If you then want the traceback, you can add in a lone "raise" statement below the excepts. For example:
try:
buggy_code()
except ValueError:
print("Woah, you did something you shouldn't have")
raise
except TypeError:
print("Woah, you did something ELSE you shouldn't have")
raise
Errors have evolved to be a lot more useful in modern times. They don't break the entire system anymore, and there are ways of handling them. Try/Except blocks like the above give you the tools to have code that only executes when a specific error or set of errors is raised.
Here's the original code:
res.write JSON.stringify {"#{result.statusCode}": "OK"}
and here's the error that both the CoffeeScript linter in SublimeText 2 and the "Try CoffeeScript" interpreter on the CoffeeScript site give me:
PARSE ERROR ON LINE 1: UNEXPECTED '('
Obviously there's no open parens in the code, so I don't understand the error. Is it a bug in the CoffeeScript parser?
The smallest line of code that does this seems to be something like this:
{"#{a}": ""}
I'm assuming that string interpolation in an object's key is valid, but I don't know for sure.
EDIT:
After some investigation it seems that it's not valid to do the string interpolation in the key because the resulting JavaScript would be invalid.
This:
{"#{a}": "stuff}
would translate to something like:
{ "" + a: "stuff"}
which isn't valid.
But can someone explain why the error message it gives me is so wrong?
I'm assuming that string interpolation in an object's key is valid, but I don't know for sure.
Unfortunately it's not.
You'll have to do something like
(json = {})[result.statusCode] = 'OK'
res.write JSON.stringify json
or if you want a one-liner
res.write (-> ((json = {})[result.statusCode] = 'OK') and JSON.stringify json)()
As for the misleading error, CoffeeScript is trying to translate your {"#{a}": ''} into {("" + a): ""} which is not valid JavaScript. CoffeeScript is throwing the error at that left paren.
The dt.Select(string) gives error missing operand when apostrophe symbol is in the string.
what is the way to solve this error? or How to handle this error?
String value = "Rubens' Home"; // value you want to sanitize and search
dt.Select(String.Format(
"Location = '{0}'", value.Replace("'", "''")));