Checking whether a string is convertible to an integer

Question

I wanted to check whether a string is convertible to an integer inside lambda expression.

import re,time
rdd = sc.textFile("file:///home/vdpqa/sample.gz")
new1 = rdd.map(lambda x: re.split('/|\.|\|',x))
    .filter(lambda arr: (len(arr) > 9) and isinstance(arr[7],int)).map(lambda x: x[:9])

new = new1.map(lambda x: [x[0],x[1],x[3],
        time.strftime('%Y%m%d', time.localtime(int(x[7])/1000000)),x[8]])

I checked this question but it didn't help:

>>> isinstance(1448379000595770,int)
True
>>> isinstance('1448379000595770',int)
False

I would recommend ditching the `lambda`s and just defining ordinary functions. — TigerhawkT3, Dec 03 '15 at 14:34
The surest way is to try and cast the string to an int and see if it raises an exception. And probably not in a lambda function. — khelwood, Dec 03 '15 at 14:37

score 5 · Answer 1 · edited Aug 20 '21 at 06:43

5

In an ordinary function the best approach would be:

def canBeNumber(n):
    try:
        int(n)
        return True
    except ValueError:
        # Not a number
        return False

edited Aug 20 '21 at 06:43

mka

153
5

answered Dec 03 '15 at 14:38

elzell

2,228
1
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Checking whether a string is convertible to an integer

1 Answers1