Reading and Writing

TODO: Improve

Reading

As mentioned earlier, the Python input statement is used to read data from stdin (possibly with a prompt previously shown on stdout).

However, using input has limitations, as it only allows reading one line of text. To address these issues and obtain a more precise and efficient way to read data, in this course we will use the yogi package. This way, we can overcome the limitations of input and improve the data reading process. To use the yogi package, it must be installed beforehand (with pip3 install yogi).

To use the yogi package, you need to do an import yogi (similar to import turtle). yogi offers a read function that allows reading integer, real, or textual data. You must specify which type of data you want to read as a parameter: int for integers, float for real numbers, or str for texts (words, specifically):

>>> import yogi
>>> i = yogi.read(int)
12
>>> i
12
>>> f = yogi.read(float)
3.14
>>> f
3.14
>>> s = yogi.read(str)
September
>>> s
'September'

Thanks to yogi, data can be read even if they are on the same or different lines. For example, the following statement reads two integers and writes their sum.

>>> print(yogi.read(int) + yogi.read(int))
3 4
7

And it also works with data separated by many spaces or lines:

>>> print(yogi.read(int) + yogi.read(int))


3



          4
7

Achieving this with input is practically impossible.

If data of a type not prescribed is read, an error will occur. For example:

>>> i = yogi.read(int)
23.56
ValueError: invalid literal for int() with base 10: '23.56'

yogi offers more operations, which we will see later, but before finishing, note that you can import a function directly from a package so you don't have to prefix it with the package name every time:

>>> from yogi import read
>>> print(read(int) + read(int))

In long programs, it is not advisable to use the from ... import ... form, but for short or throwaway programs, it is worth it.