Add and increment number to the end of numerical or non-numerical string python

Question

I am reading a JSON file with data in it and I am trying to ensure that each file that is created in my code has a unique value. However sometimes the value is a string either like "data" or some number as a string

So if the file I are creating 3 times is called "data", I want to convert it into:

data_0
data_1
data_2

Also if the value is the a number (but it string format) such as 145 I want to change that to:

145
146
147

Currently my code produces something like this:

data_0, 
data_0_1, 
data_0_1_2

or

145_0, 
145_0_1, 
145_0_1_2

Below is my code:

for index in range(0,len(test)):
      test[index]["value"]= test[index]["value"] + str(number)

I am using str(number) because otherwise I get this error:

TypeError: coercing to Unicode: need string or buffer, int found

JSON file example:

"test": [{
    "type": "text",
    "value": "data"
}, {
    "type": "integer",
    "value": "145"
}]

Any advice would be appreciated.

@Borja It is a json file that I import and read in python, which is working correctly for me. That is the json format. — Catherine, Mar 21 '16 at 14:20
It's the first time you mention the word `json` in your post. Please, always be very specific. — Avión, Mar 21 '16 at 14:21
Can you please clarify the question? What is wrong with your code? How would you like to improve it? — Yaron, Mar 21 '16 at 14:26
@Yaron My code produces data_0, data_0_1, data_0_1_2 or 145_0, 145_0_1,145_0_1_2 instead of producing data_0, data_1, data_2 or 145, 146, 147 — Catherine, Mar 21 '16 at 14:35
At his time, your code produces `data0`, `data1`, if you want to get `data_0`, `data_1` you should use `test[index]["value"]= test[index]["value"] + "_" + str(number)` — Avión, Mar 21 '16 at 14:36

score 1 · Accepted Answer · answered Mar 21 '16 at 14:48

You can use a try & catch to check if the input is an integer or a string. If it's an int you sum 1 to the number, if it's a string you just append the _index.

test = [{"type": "text", "value": "data"}, {"type": "integer","value": "145"}]

for index in range(0,len(test)):
    try:
        # Test if the value is an integer
        test[index]["value"]= int(test[index]["value"]) + index

    except ValueError:
        # The value is an string
        test[index]["value"]= test[index]["value"] + "_" + str(index)

print test

Outputs:

[{'type': 'text', 'value': 'data_0'}, {'type': 'integer', 'value': 146}]

score 0 · Answer 2 · edited May 23 '17 at 12:15

0

Borja's answer is good and follows the EAFP principle. Your code can be cleaned up a little if you use enumerate and str.format.

for index, dictionary in enumerate(test):
    try:
        dictionary['value'] = int(dictionary['value']) + 1

    except ValueError:
        dictionary['value'] += '_{}'.format(index)

edited May 23 '17 at 12:15

Community

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answered Mar 21 '16 at 15:38

Jared Goguen

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Add and increment number to the end of numerical or non-numerical string python

2 Answers2