mirror of
https://github.com/Xevion/exercism.git
synced 2025-12-14 14:11:41 -06:00
129 lines
3.4 KiB
Markdown
129 lines
3.4 KiB
Markdown
# OCR Numbers
|
|
|
|
Given a 3 x 4 grid of pipes, underscores, and spaces, determine which number is
|
|
represented, or whether it is garbled.
|
|
|
|
# Step One
|
|
|
|
To begin with, convert a simple binary font to a string containing 0 or 1.
|
|
|
|
The binary font uses pipes and underscores, four rows high and three columns wide.
|
|
|
|
```text
|
|
_ #
|
|
| | # zero.
|
|
|_| #
|
|
# the fourth row is always blank
|
|
```
|
|
|
|
Is converted to "0"
|
|
|
|
```text
|
|
#
|
|
| # one.
|
|
| #
|
|
# (blank fourth row)
|
|
```
|
|
|
|
Is converted to "1"
|
|
|
|
If the input is the correct size, but not recognizable, your program should return '?'
|
|
|
|
If the input is the incorrect size, your program should return an error.
|
|
|
|
# Step Two
|
|
|
|
Update your program to recognize multi-character binary strings, replacing garbled numbers with ?
|
|
|
|
# Step Three
|
|
|
|
Update your program to recognize all numbers 0 through 9, both individually and as part of a larger string.
|
|
|
|
```text
|
|
_
|
|
_|
|
|
|_
|
|
|
|
```
|
|
|
|
Is converted to "2"
|
|
|
|
```text
|
|
_ _ _ _ _ _ _ _ #
|
|
| _| _||_||_ |_ ||_||_|| | # decimal numbers.
|
|
||_ _| | _||_| ||_| _||_| #
|
|
# fourth line is always blank
|
|
```
|
|
|
|
Is converted to "1234567890"
|
|
|
|
# Step Four
|
|
|
|
Update your program to handle multiple numbers, one per line. When converting several lines, join the lines with commas.
|
|
|
|
```text
|
|
_ _
|
|
| _| _|
|
|
||_ _|
|
|
|
|
_ _
|
|
|_||_ |_
|
|
| _||_|
|
|
|
|
_ _ _
|
|
||_||_|
|
|
||_| _|
|
|
|
|
```
|
|
|
|
Is converted to "123,456,789"
|
|
|
|
## Exception messages
|
|
|
|
Sometimes it is necessary to raise an exception. When you do this, you should include a meaningful error message to
|
|
indicate what the source of the error is. This makes your code more readable and helps significantly with debugging. Not
|
|
every exercise will require you to raise an exception, but for those that do, the tests will only pass if you include
|
|
a message.
|
|
|
|
To raise a message with an exception, just write it as an argument to the exception type. For example, instead of
|
|
`raise Exception`, you should write:
|
|
|
|
```python
|
|
raise Exception("Meaningful message indicating the source of the error")
|
|
```
|
|
|
|
## Running the tests
|
|
|
|
To run the tests, run the appropriate command below ([why they are different](https://github.com/pytest-dev/pytest/issues/1629#issue-161422224)):
|
|
|
|
- Python 2.7: `py.test ocr_numbers_test.py`
|
|
- Python 3.4+: `pytest ocr_numbers_test.py`
|
|
|
|
Alternatively, you can tell Python to run the pytest module (allowing the same command to be used regardless of Python version):
|
|
`python -m pytest ocr_numbers_test.py`
|
|
|
|
### Common `pytest` options
|
|
|
|
- `-v` : enable verbose output
|
|
- `-x` : stop running tests on first failure
|
|
- `--ff` : run failures from previous test before running other test cases
|
|
|
|
For other options, see `python -m pytest -h`
|
|
|
|
## Submitting Exercises
|
|
|
|
Note that, when trying to submit an exercise, make sure the solution is in the `$EXERCISM_WORKSPACE/python/ocr-numbers` directory.
|
|
|
|
You can find your Exercism workspace by running `exercism debug` and looking for the line that starts with `Workspace`.
|
|
|
|
For more detailed information about running tests, code style and linting,
|
|
please see [Running the Tests](http://exercism.io/tracks/python/tests).
|
|
|
|
## Source
|
|
|
|
Inspired by the Bank OCR kata [http://codingdojo.org/cgi-bin/wiki.pl?KataBankOCR](http://codingdojo.org/cgi-bin/wiki.pl?KataBankOCR)
|
|
|
|
## Submitting Incomplete Solutions
|
|
|
|
It's possible to submit an incomplete solution so you can see how others have completed the exercise.
|