拆分用户输入并在Python字符串中添加字符

Question

I have a Python script that accepts user input (it is scanned with a barcode) that subsequently generates a CSV file with all of the user's data. This CSV file is then used to drive a Crystal Report.

The input consists of a single string of concatenated fields delimited by a space- Item #, Lot #, and Quantity.

    Example: G00177 LOT12345 24

The problem, however, is that the Item # OR Lot # could potentially be numeric instead of a string:

    Example 1: G00177 12345 24
    Example 2: 00177 12345 24

My thought was to append a character to the beginning of the Item # and Lot #, forcing it into a string, and then using Crystal to automatically suppress the added character.

So far, I have only been able to add a character to the beginning of the Item #- not the Lot #. I also do not want to append to the Quantity field as it will always be numeric.

Any criticism, insight, or suggestions are greatly appreciated.

I am just learning with Python and I know my approach is not the best.

Thank you for your time.

Answer 1

You can try something like this:

report_one = '00177 12345 24'
report_two = 'G0177 12345 24'
report_three = 'G0177 I2345 24'

def convert(original):
    s = original.split()
    for i in range(2):       # 2 is used here because that's how many 'words'
        try:                 #     we want to check for numeric-ness. This can
            int(s[i])        #     be adjusted if you have to change your schema
        except ValueError:   #     at some point in the future.
            s[i] += 'S'
    return ' '.join(s)

print convert(report_one)    # Prints 00177 12345 24
print convert(report_two)    # Prints G0177S 12345 24
print convert(report_three)  # Prints G0177S I2345S 24

This first splits up the string into its individual words. You know that the first and the second ones are potentially integers, and you need a way for the next system to understand them as strings.

Using the split words, doing a cast on the word into an int under a try block will throw a ValueError if the string is not an integer. That is, if it contains any letters, the except ValueError clause will kick in. At this point, you can simply append a letter to the end, and have your next system scan the word for that ending letter (here my example uses an 'S' ).

If you want to append a letter to the beginning, you can replace s[i] += 'S' with: s[i] = 'S' + s[i]