TypeError: ‘list’ object is not callable while trying to access a list
For accessing the elements of a list you need to use the square brackets ([]) and not the parenthesis (()). Instead of: you need to use: And instead of: you need to use:
Why in C++ do we use DWORD rather than unsigned int? [duplicate]
DWORD is not a C++ type, it’s defined in <windows.h>. The reason is that DWORD has a specific range and format Windows functions rely on, so if you require that specific range use that type. (Or as they say “When in Rome, do as the Romans do.”) For you, that happens to correspond to unsigned int, but that might not …
List of All Locales and Their Short Codes?
The importance of locales is that your environment/os can provide formatting functionality for all installed locales even if you don’t know about them when you write your application. My Windows 7 system has 211 locales installed (listed below), so you wouldn’t likely write any custom code or translation specific to this many locales. Edit: The …
How do I pause my shell script for a second before continuing?
Use the sleep command. Example: One can also employ decimals when specifying a time unit; e.g. sleep 1.5s
Why has the int32 type a maximum value of 2³¹ − 1? [duplicate]
Possible Duplicate:What is “2’s Complement”? I know int32 has a length of 32 bits (4 bytes). I assume it has 2³² values but as half of them must be under zero, I guess it has something to do with this. I would like to know why exactly int32 has max. positive number 2³¹ − 1.
What throws an IOException in Java?
Assume you were: Reading a network file and got disconnected. Reading a local file that was no longer available. Using some stream to read data and some other process closed the stream. Trying to read/write a file, but don’t have permission. Trying to write to a file, but disk space was no longer available. There …
Arduino Sketch upload issue – avrdude: stk500_recv(): programmer is not responding
I had this problem with a Crowduino, running the Arduino IDE on OS X. The solution for me was to switch on verbose output during upload (in the Arduino IDE preferences pane). Then, when uploading, you can see AVRDUDE sending three packets avrdude: Send: 0 [30] [20] (with corresponding RX flashes on the board) right before the avrdude: ser_recv(): programmer is …
ValueError: invalid literal for int() with base 10: ”
I am creating a program that reads a file and if the first line of the file is not blank, it reads the next four lines. Calculations are performed on those lines and then the next line is read. If that line is not empty it continues. However, I am getting this error: ValueError: invalid …
Why do we need virtual functions in C++?
Here is how I understood not just what virtual functions are, but why they’re required: Let’s say you have these two classes: In your main function: So far so good, right? Animals eat generic food, cats eat rats, all without virtual. Let’s change it a little now so that eat() is called via an intermediate function (a trivial function just …
Check if a given key already exists in a dictionary
in is the intended way to test for the existence of a key in a dict. If you wanted a default, you can always use dict.get(): and if you wanted to always ensure a default value for any key you can either use dict.setdefault() repeatedly or defaultdict from the collections module, like so: but in …
