Correct and incorrect variable names

Note that the same restrictions apply to function names.

Python does not impose restrictions on the length of variable names, but that doesn't mean that a long variable name is always better than a short one.

Here are some correct, but not always convenient variable names:

MyVariable, i, t34, Exchange_Rate, counter, days_to_christmas, TheNameIsSoLongThatYouWillMakeMistakesWithIt, _.

Moreover, Python lets you use not only Latin letters but also characters specific to languages that use other alphabets.

These variable names are also correct:

Adiós_Señora, sûr_la_mer, Einbahnstraße, переменная.

And now for some incorrect names:

10t (does not begin with a letter), Exchange Rate (contains a space)