Xah Lee, 2005-01-10, 2011-07-22
Substring extraction is done by appending a bracket [] with begin and ending index.
#-*- coding: utf-8 -*- # python a="this and that" print a[3:6] # prints “s a” b="01234567" print b[3:6] # prints “345”
The easiest way to make sense of python's indexing is to to think that the index goes between the chars, not on the char, and index starts at 0.
The index can be negative, which counts from the end.
a="this and that" print a[3:-2] # prints “s and th”
Length of the string is len().
a="this" print len(a) # 4
Strings can be joined by a plus sign +.
print "this" + " that"
String can be repeated using *.
print "this" * 2
String extraction is done with substr().
The form is: substr($myString, offset index, number of characters to extract).
print substr('abcdefg',2,3); # prints cde
Length of string is length().
print length('abc');
In Perl, string join is done with a dot.
$astr= "under" . "stand";
String repeatition is done with the the letter x.
print 'abc' x 2;