ValueError: invalid literal for int() with base 10: ”

110 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: … Read more

Why are #ifndef and #define used in C++ header files?

Those are called #include guards. Once the header is included, it checks if a unique value (in this case HEADERFILE_H) is defined. Then if it’s not defined, it defines it and continues to the rest of the page. When the code is included again, the first ifndef fails, resulting in a blank file. That prevents … Read more

Amazon Linux: apt-get: command not found

If you’re using Amazon Linux it’s CentOS-based, which is RedHat-based. RH-based installs use yum not apt-get. Something like yum search httpd should show you the available Apache packages – you likely want yum install httpd24. Note: Amazon Linux 2 has diverged from CentOS since the writing of this answer, but still uses yum.

Use Notepad++ as HEX-Editor

It seems to me you tried to install a hex editor and ended up in the wrong tool (Plug-In) Converter (ASCII -> HEX) as mentioned in your question above. The installation process of the HexEditor is somewhat confusing because it is currently available only in the Plugins Admin for the 32-bit version. A simple solution … Read more

ImportError: No module named matplotlib.pyplot

You have two pythons installed on your machine, one is the standard python that comes with Mac OSX and the second is the one you installed with ports (this is the one that has matplotlib installed in its library, the one that comes with macosx does not). Is the standard mac python and since it … Read more

Converting string into datetime

datetime.strptime is the main routine for parsing strings into datetimes. It can handle all sorts of formats, with the format determined by a format string you give it: The resulting datetime object is timezone-naive. Links: Python documentation for strptime: Python 2, Python 3 Python documentation for strptime/strftime format strings: Python 2, Python 3 strftime.org is … Read more

Invariant Violation: Objects are not valid as a React child

In my component’s render function I have: everything renders fine, however when clicking the <li> element I receive the following error: Uncaught Error: Invariant Violation: Objects are not valid as a React child (found: object with keys {dispatchConfig, dispatchMarker, nativeEvent, target, currentTarget, type, eventPhase, bubbles, cancelable, timeStamp, defaultPrevented, isTrusted, view, detail, screenX, screenY, clientX, clientY, … Read more