CODEWITHSUNDEEP
python
rajachan
rajachan

Reputation: 795

Python: Comparing string variable against multiple sub-strings

I am new to Python and trying to learn python from Perl. In Perl, if I want to compare a string against multiple sub-strings, I would use the following:

sub matchCity {
    my $cityName = shift;
    print "$cityName is a valid city name\n" if ($cityName =~ /kyo|par|omba/);
}

matchCity('tokyo'); # tokyo is a valid city name
matchCity('paris'); # paris is a valid city name
matchCity('bombay'); # bombay is a valid city name
matchCity('chicago'); # Doesn't print anything

How can I do this in python?

Upvotes: 1

Views: 159

Answers (4)

John La Rooy
John La Rooy

Reputation: 304147

import re

def matchCity(city_name):
    if re.search('kyo|par|omba', city_name):
        print "{} is a valid city name".format(city_name)

matchCity('tokyo') # tokyo is a valid city name
matchCity('paris') # paris is a valid city name
matchCity('bombay') # bombay is a valid city name
matchCity('chicago') # Doesn't print anything

Upvotes: 2

Matimus
Matimus

Reputation: 512

Python has regular expressions. So you could do this:

import re

city_names = re.compile(r'kyo|par|omba')

def match_city(city_name):
    if city_names.search(city_name):
        print city_name, "is a valid city name"

Normally I would tell you to avoid regular expressions if you can. But matching one of multiple sub-strings is actually a case where they likely perform better than a loop. This is especially true as the number of sub-strings grows.

Upvotes: 0

LeartS
LeartS

Reputation: 2896

With regular expressions:

import re
city = re.compile('kyo|par|omba', re.I)
matchCity = lambda x: city.search(x)

And you can use matchCity("example_city") as condition:

if matchCity("tokyo"):   print "Valid city!" # Valid city!
if matchCity("paris"):   print "Valid city!" # Valid city!
if matchCity("bombay"):  print "Valid city!" # Valid city!
if matchCity("chicago"): print "Valid city!" #

Upvotes: 0

arshajii
arshajii

Reputation: 129507

You don't actually need regex for this:

>>> def matchCity(s):
...     if any(r in s for r in ('kyo','par','omba')):
...         print s, 'is a valid city name'
... 
>>> matchCity('tokyo')
tokyo is a valid city name
>>> matchCity('paris')
paris is a valid city name
>>> matchCity('bombay')
bombay is a valid city name
>>> matchCity('chicago')  # doesn't print anything
>>>

Upvotes: 3

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