In Python 3, you can use the sep= and end= parameters of the print function: To not add a newline to the end of the string: To not add a space between all the function arguments you want to print: You can pass any string to either parameter, and you can use both parameters at … Read more
Short Answer It’s boilerplate code that protects users from accidentally invoking the script when they didn’t intend to. Here are some common problems when the guard is omitted from a script: If you import the guardless script in another script (e.g. import my_script_without_a_name_eq_main_guard), then the second script will trigger the first to run at import … Read more
Close: first you call ExcelFile, but then you call the .parse method and pass it the sheet name. What you’re doing is calling the method which lives on the class itself, rather than the instance, which is okay (although not very idiomatic), but if you’re doing that you would also need to pass the sheet … Read more
Every minor version of Python, that is any 3.x and 2.x version, will install side-by-side with other versions on your computer. Only patch versions will upgrade existing installations. So if you want to keep your installed Python 2.7 around, then just let it and install a new version using the installer. If you want to … Read more
r is a numpy (rec)array. So r[“dt”] >= startdate is also a (boolean) array. For numpy arrays the & operation returns the elementwise-and of the two boolean arrays. The NumPy developers felt there was no one commonly understood way to evaluate an array in boolean context: it could mean True if any element is True, … Read more
The % (modulo) operator yields the remainder from the division of the first argument by the second. The numeric arguments are first converted to a common type. A zero right argument raises the ZeroDivisionError exception. The arguments may be floating point numbers, e.g., 3.14%0.7 equals 0.34 (since 3.14 equals 4*0.7 + 0.34.) The modulo operator … Read more
Here is some list functions based on Martin v. Löwis’s representation: where w = sys.stdout.write Although doubly linked lists are famously used in Raymond Hettinger’s ordered set recipe, singly linked lists have no practical value in Python. I’ve never used a singly linked list in Python for any problem except educational. Thomas Watnedal suggested a … Read more
The current answers are good, but do not talk about how they are just syntactic sugar to some pattern that we are so used to. Let’s start with an example, say we have 10 numbers, and we want a subset of those that are greater than, say, 5. For the above task, the below approaches … Read more
item is most likely a string in your code; the string indices are the ones in the square brackets, e.g., gravatar_id. So I’d first check your data variable to see what you received there; I guess that data is a list of strings (or at least a list containing at least one string) while it … Read more
How about: This is extended slice syntax. It works by doing [begin:end:step] – by leaving begin and end off and specifying a step of -1, it reverses a string.