PYTHON substr

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Python replacement for PHP's substr [ edit | history ]
use slices:

PHP:
substr("abcdef", start, length);


Python:
string[start:start+length]


Example:
substr("abcdef", 2, 3);

>>> 'abcdef'[2:5]
'cde'


or as a function:
def substr (self, s, start, length = None):
        """Returns the portion of string specified by the start and length 
        parameters.
        """
       if len(s) >= start:
            if start > 0:
                return False
            else:
                return s[start:]
        if not length:
            return s[start:]
        elif length > 0:
            return s[start:start + length]
        else:
            return s[start:length]

PHP substr

PHP original manual for substr [ show | php.net ]

substr

(PHP 4, PHP 5)

substrReturn part of a string

Description

string substr ( string $string , int $start [, int $length ] )

Returns the portion of string specified by the start and length parameters.

Parameters

string

The input string.

start

If start is non-negative, the returned string will start at the start 'th position in string , counting from zero. For instance, in the string 'abcdef', the character at position 0 is 'a', the character at position 2 is 'c', and so forth.

If start is negative, the returned string will start at the start 'th character from the end of string .

If string is less than or equal to start characters long, FALSE will be returned.

Example #1 Using a negative start

<?php
$rest 
substr("abcdef", -1);    // returns "f"
$rest substr("abcdef", -2);    // returns "ef"
$rest substr("abcdef", -31); // returns "d"
?>

length

If length is given and is positive, the string returned will contain at most length characters beginning from start (depending on the length of string ).

If length is given and is negative, then that many characters will be omitted from the end of string (after the start position has been calculated when a start is negative). If start denotes a position beyond this truncation, an empty string will be returned.

Example #2 Using a negative length

<?php
$rest 
substr("abcdef"0, -1);  // returns "abcde"
$rest substr("abcdef"2, -1);  // returns "cde"
$rest substr("abcdef"4, -4);  // returns ""
$rest substr("abcdef", -3, -1); // returns "de"
?>

Return Values

Returns the extracted part of string.

Examples

Example #3 Basic substr() usage

<?php
echo substr('abcdef'1);     // bcdef
echo substr('abcdef'13);  // bcd
echo substr('abcdef'04);  // abcd
echo substr('abcdef'08);  // abcdef
echo substr('abcdef', -11); // f

// Accessing single characters in a string
// can also be achieved using "square brackets"
$string 'abcdef';
echo 
$string[0];                 // a
echo $string[3];                 // d
echo $string[strlen($string)-1]; // f

?>

See Also

  • strrchr() - Find the last occurrence of a character in a string
  • substr_replace() - Replace text within a portion of a string
  • preg_match() - Perform a regular expression match
  • trim() - Strip whitespace (or other characters) from the beginning and end of a string
  • mb_substr() - Get part of string
  • wordwrap() - Wraps a string to a given number of characters