Comma quibbling: Difference between revisions

=={{header|Python}}==▼

===replace() whilst reversed===▼

replace(..) can only replace the first X occurrences not the last▼

hence the replace is done on the reverse of the intermediate string▼

then reversed back.▼

<lang python>>>> def strcat(sequence):▼

return '{%s}' % ', '.join(sequence)[::-1].replace(',', 'dna ', 1)[::-1]▼

>>> for seq in ([], ["ABC"], ["ABC", "DEF"], ["ABC", "DEF", "G", "H"]):▼

print('Input: %-24r -> Output: %r' % (seq, strcat(seq)))▼

▼

Input: [] -> Output: '{}'▼

Input: ['ABC'] -> Output: '{ABC}'▼

Input: ['ABC', 'DEF'] -> Output: '{ABC and DEF}'▼

Input: ['ABC', 'DEF', 'G', 'H'] -> Output: '{ABC, DEF, G and H}'▼

>>> </lang>▼

===Counted replacement===▼

(Possible){{trans|Tcl}}▼

replace() will replace nothing if the count of items to replace is zero, (and negative integer counts act to replace all occurrences).▼

This combines with the length of the input sequence to allow this to work:▼

<lang python>def commaQuibble(s):▼

return '{%s}' % ' and '.join(s).replace(' and ', ', ', len(s) - 2)▼

for seq in ([], ["ABC"], ["ABC", "DEF"], ["ABC", "DEF", "G", "H"]):▼

print('Input: %-24r -> Output: %r' % (seq, commaQuibble(seq)))</lang>▼

{{out}}▼

<pre>Input: [] -> Output: '{}'▼

Input: ['ABC'] -> Output: '{ABC}'▼

Input: ['ABC', 'DEF'] -> Output: '{ABC and DEF}'▼

Input: ['ABC', 'DEF', 'G', 'H'] -> Output: '{ABC, DEF, G and H}'</pre>▼