regex101: Python Match Workspace

Group content(?P<content>.*?)

.*?any Unicode character, repeated any number of times

Comment: Content up to next tag

Group markup(?P<markup> # Entire tag <!\[CDATA\[(?P<cdata>.+?)]]>| # <![CDATA[ ... ]]> | #  </\s*(?P<close_tag>\w+)\s*>| # </tag> <(?P<tag>\w+) # <tag ... (?P<attributes> (?P<attribute>\s+ # <snip>: Use this part to get the attributes out of 'attributes' group. (?P<attribute_name>\w+) (?:\s*=\s* (?P<attribute_value> [\w:/.\-]+| # Unquoted (?=(?P<_v> # Quoted (?P<_q>['\"]).*?(?<!\\)(?P=_q))) (?P=_v) ))? # </snip> )* )\s* (?P<is_self_closing>/?) # Self-closing indicator >)

1st Alternative # Entire tag <!\[CDATA\[(?P<cdata>.+?)]]>

Comment: Entire tag

<!the literal text <!

\[the literal [ (91₁₀ / 133₈ / 5B₁₆)

CDATAthe literal text CDATA (case sensitive)

\[the literal [ (91₁₀ / 133₈ / 5B₁₆)

Group cdata(?P<cdata>.+?)

.+?any Unicode character, repeated at least once

]]>the literal text ]]>

2nd Alternative # <![CDATA[ ... ]]>

Comment: <![CDATA[ ... ]]>

<!--the literal text <!--

Group comment(?P<comment>.+?)

.+?any Unicode character, repeated at least once

-->the literal text -->

3rd Alternative #  </\s*(?P<close_tag>\w+)\s*>

Comment:

</the literal text </

\s*a Unicode whitespace character, repeated any number of times

Group close_tag(?P<close_tag>\w+)

\w+a Unicode word character, repeated at least once

\s*a Unicode whitespace character, repeated any number of times

>the literal > (62₁₀ / 76₈ / 3E₁₆)

4th Alternative # </tag> <(?P<tag>\w+) # <tag ... (?P<attributes> (?P<attribute>\s+ # <snip>: Use this part to get the attributes out of 'attributes' group. (?P<attribute_name>\w+) (?:\s*=\s* (?P<attribute_value> [\w:/.\-]+| # Unquoted (?=(?P<_v> # Quoted (?P<_q>['\"]).*?(?<!\\)(?P=_q))) (?P=_v) ))? # </snip> )* )\s* (?P<is_self_closing>/?) # Self-closing indicator >

Comment: </tag>

<the literal text <

Group tag(?P<tag>\w+)

\w+a Unicode word character, repeated at least once

Comment: <tag ...

Group attributes(?P<attributes> (?P<attribute>\s+ # <snip>: Use this part to get the attributes out of 'attributes' group. (?P<attribute_name>\w+) (?:\s*=\s* (?P<attribute_value> [\w:/.\-]+| # Unquoted (?=(?P<_v> # Quoted (?P<_q>['\"]).*?(?<!\\)(?P=_q))) (?P=_v) ))? # </snip> )* )

Group attribute(?P<attribute>\s+ # <snip>: Use this part to get the attributes out of 'attributes' group. (?P<attribute_name>\w+) (?:\s*=\s* (?P<attribute_value> [\w:/.\-]+| # Unquoted (?=(?P<_v> # Quoted (?P<_q>['\"]).*?(?<!\\)(?P=_q))) (?P=_v) ))? # </snip> )*

*repeats the group contents below any number of times:

\s+a Unicode whitespace character, repeated at least once

Comment: <snip>: Use this part to get the attributes out of 'attributes' group.

Group attribute_name(?P<attribute_name>\w+)

\w+a Unicode word character, repeated at least once

Non-Capturing Group(?:\s*=\s* (?P<attribute_value> [\w:/.\-]+| # Unquoted (?=(?P<_v> # Quoted (?P<_q>['\"]).*?(?<!\\)(?P=_q))) (?P=_v) ))?

?repeats the group contents below at most once:

\s*a Unicode whitespace character, repeated any number of times

=the literal = (61₁₀ / 75₈ / 3D₁₆)

\s*a Unicode whitespace character, repeated any number of times

Group attribute_value(?P<attribute_value> [\w:/.\-]+| # Unquoted (?=(?P<_v> # Quoted (?P<_q>['\"]).*?(?<!\\)(?P=_q))) (?P=_v) )

1st Alternative [\w:/.\-]+

Character Class[\w:/.\-]+

+matches at least one character from the set below:

\wa Unicode word character

:the literal : (58₁₀ / 72₈ / 3A₁₆)

/the literal / (47₁₀ / 57₈ / 2F₁₆)

.the literal . (46₁₀ / 56₈ / 2E₁₆)

\-the literal - (45₁₀ / 55₈ / 2D₁₆)

2nd Alternative # Unquoted (?=(?P<_v> # Quoted (?P<_q>['\"]).*?(?<!\\)(?P=_q))) (?P=_v)

Comment: Unquoted

Positive Lookahead(?=(?P<_v> # Quoted (?P<_q>['\"]).*?(?<!\\)(?P=_q)))

Group _v(?P<_v> # Quoted (?P<_q>['\"]).*?(?<!\\)(?P=_q))

Comment: Quoted

Group _q(?P<_q>['\"])

Character Class['\"]

'the literal ' (39₁₀ / 47₈ / 27₁₆)

\"the literal " (34₁₀ / 42₈ / 22₁₆)

.*?any Unicode character, repeated any number of times

Negative Lookbehind(?<!\\)

\\the literal \ (92₁₀ / 134₈ / 5C₁₆)

(?P=_q)the text saved by group _q

(?P=_v)the text saved by group _v

Comment: </snip>

\s*a Unicode whitespace character, repeated any number of times

Group is_self_closing(?P<is_self_closing>/?)

/?optionally matches the literal / (47₁₀ / 57₈ / 2F₁₆)

Comment: Self-closing indicator

>the literal text >

Comment: End of tag

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

s modifier: single line. Allows a dot to match line terminators

x modifier: extended. Ignores unescaped whitespace and comments outside character classes

25 tokens

Regular Expression

(?P<content>.*?)                # Content up to next tag
(?P<markup>                     # Entire tag
  <!\[CDATA\[(?P<cdata>.+?)]]>| # <![CDATA[ ... ]]>
  <!--(?P<comment>.+?)-->|      # <!-- Comment -->
  </\s*(?P<close_tag>\w+)\s*>|  # </tag>
  <(?P<tag>\w+)                 # <tag ...
    (?P<attributes>
      (?P<attribute>\s+
# <snip>: Use this part to get the attributes out of 'attributes' group.
        (?P<attribute_name>\w+)
        (?:\s*=\s*
          (?P<attribute_value>
            [\w:/.\-]+|         # Unquoted
            (?=(?P<_v>          # Quoted
              (?P<_q>['\"]).*?(?<!\\)(?P=_q)))
            (?P=_v)
          ))?
# </snip>
      )*
    )\s*
  (?P<is_self_closing>/?)   # Self-closing indicator
  >)                        # End of tag

New

In this case, $url will indeed contain http://example.com/whatever.jpg. But what happens when you start getting HTML like this:

<img src='http://example.com/whatever.jpg'>
or

<img src=http://example.com/whatever.jpg>
or

<img border=0 src="http://example.com/whatever.jpg">
or

<img border src="http://example.com/whatever.jpg">
or

<img
    src="http://example.com/whatever.jpg">
or you start getting false positives from

<!-- // commented out
<img src="http://example.com/outdated.png">
-->

<script><![CDATA[ This is <b>not</b> parsed ]]></script>

<asd ASD=asd>

<!-- // commented out <img src="http://example.com/outdated.png"> -->

No quotes:
<iframe src=test.html target=xyz></ iframe >
Self-closing tag:
<a href=test.html target=xyz/>
Self closing tag with a space before closure:
<a href=test.html target=xyz />
Double quotes:
<a href="test.html" target="xyz">
Single quotes:
<a href='test.html' target='xyz'>
Escaping double quotes:
<a href="test.html?val=1" title="\"No rules exist\" Andre Breton's quote">
Escaping single quotes (also with spaces between equals signs):
<a href = "test.html?val=1" title = 'Charlie\'s Angels'>
Tag without closure (ignored):
<a href = "test.html?val=1" title='Charlie\'s Angels'
Tag without opening (ignored):
a href = "test.html?val=1" title="Charlie\"s Angels">

Regular Expressions 101

Regular Expression

Substitution