Check numeric values from a dictionary by unit test

Question

I have a function

read_value_from_text()

that reads parameters from a config file and returns a dictionary in this form

{ key1 : value1, key2 : value2, ... , keyn : valuen }

the values (value1 ... valuen) are all strings that represent numbers. I want to write a unit test that checks if all values (value1,...,valuen) are "numeric" ( float or integer). Can someone suggest an efficient way to do this?

score 2 · Accepted Answer · edited May 23 '17 at 12:14

2

You can test whether a string is a number with:

def is_number(s):
    try:
        float(s)
        return True
    except ValueError:
        return False

is_number(x)

You can thus do:

self.assertTrue(all(is_number(v) for v in d.itervalues()))

edited May 23 '17 at 12:14

Community

1
1

answered Apr 21 '15 at 17:47

David Robinson

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Sorry I was not clear in the question... value1... valuen are all string that rapresent numbers Like '1' or '2.3' In this case the function isinstance fails – overcomer Apr 21 '15 at 18:04
@overcomer I understand now. Corrected (see [here](http://stackoverflow.com/questions/354038/how-do-i-check-if-a-string-is-a-number-float-in-python) for more on that function) – David Robinson Apr 21 '15 at 18:09

score 1 · Answer 2 · answered Apr 21 '15 at 18:15

def isNumeric(val):
    if isinstance(val, (int, float)):
        return True
    try:
        float(val)
    except ValueError:
        return False
    else:
        return True

Sample test:

d = {}
for v in d.itervalues():
    self.assertTrue(isNumeric(v))

Well, to be honest it's validator, not unit test. Unit tests are checking code behaviour, you're checking data correctness.

score 0 · Answer 3 · answered Apr 21 '15 at 17:46

0

for val in my_dict.values():
    self.assertIsInstance(val, int)

answered Apr 21 '15 at 17:46

dursk

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Will fail in case val is float, see OP. – boardrider Apr 22 '15 at 11:41

Check numeric values from a dictionary by unit test

3 Answers3