Determine if a string has all unique characters: Difference between revisions

=== Using regular expression ===

<lang python>import re

pattern = '(.)' + '.*?' + r'\1'

def find_dup_char(subject):

match = re.search(pattern, subject)

if match:

return match.groups(0)[0], match.start(0), match.end(0)

def report_dup_char(subject):

dup = find_dup_char(subject)

prefix = f'"{subject}" ({len(subject)})'

if dup:

ch, pos1, pos2 = dup

print(f"{prefix}: '{ch}' (0x{ord(ch):02x}) duplicates at {pos1}, {pos2-1}")

else:

print(f"{prefix}: no duplicate characters")

show = report_dup_char

show('coccyx')

show('')

show('.')

show('abcABC')

show('XYZ ZYX')

show('1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ')

</lang>

{{out}}

<pre>"coccyx" (6): 'c' (0x63) duplicates at 0, 2

"" (0): no duplicate characters

"." (1): no duplicate characters

"abcABC" (6): no duplicate characters

"XYZ ZYX" (7): 'X' (0x58) duplicates at 0, 6

"1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ" (36): '0' (0x30) duplicates at 9, 24

</pre>