I am trying to match strings which can be typed from a normal english keyboard.
So, it should include alphabets, digits, and all symbols present on our keyboard.
Corresponding regex : "[a-zA-Z0-9\t ./,<>?;:\"'`!##$%^&*()\[\]{}_+=|\\-]+"
I verfied this regex on regexr.com.
In python, on matching I am getting following error :
>>> a=re.match("+how to block a website in edge",pattern)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "C:\local\Anaconda3-4.1.1-Windows-x86_64\envs\tf_1.2\lib\re.py", line 163, in match
return _compile(pattern, flags).match(string)
File "C:\local\Anaconda3-4.1.1-Windows-x86_64\envs\tf_1.2\lib\re.py", line 293, in _compile
p = sre_compile.compile(pattern, flags)
File "C:\local\Anaconda3-4.1.1-Windows-x86_64\envs\tf_1.2\lib\sre_compile.py", line 536, in compile
p = sre_parse.parse(p, flags)
File "C:\local\Anaconda3-4.1.1-Windows-x86_64\envs\tf_1.2\lib\sre_parse.py", line 829, in parse
p = _parse_sub(source, pattern, 0)
File "C:\local\Anaconda3-4.1.1-Windows-x86_64\envs\tf_1.2\lib\sre_parse.py", line 437, in _parse_sub
itemsappend(_parse(source, state, nested + 1))
File "C:\local\Anaconda3-4.1.1-Windows-x86_64\envs\tf_1.2\lib\sre_parse.py", line 638, in _parse
source.tell() - here + len(this))
sre_constants.error: nothing to repeat at position 0
This error message is not about position of arguments. Yes, in question above they are not in the right order, but this is only half of problem.
I've got this problem once when i had something like this:
re.search('**myword', '/path/to/**myword')
I wanted to get '**' automatically so i did not wanted to write '\' manually somewhere. For this cause there is re.escape() function. This is the right code:
re.search(re.escape('**myword'), '/path/to/**myword')
The problem here is that special character placed after the beginning of line.
You have your arguments for re.match backward: it should be
re.match(pattern, "+how to block a website in edge")
Related
I'm working on a project that searches for filenames that match a string. The current working code appends an * to the end of the string and the code properly takes the string and matches it when there's a file extension and/or a number after, that works right. I'm wanting it to ignore things before the initial string as well to check the interior of the file name. For example File A File B.txt will be found by a string search for File A "or File B
Working code:
redeemed = redeemed + "*"
results = [file for file in sounds if re.search(redeemed, file)]
Non-working code:
redeemed = "*" + redeemed + "*"
results = [file for file in sounds if re.search(redeemed, file)]
Returns error:
Task exception was never retrieved
future: <Task finished name='Task-19' coro=<PubSub.__handle_message() done, defined at C:\Users\dmvh1\AppData\Local\Programs\Python\Python310\lib\site-packages\twitchAPI\pubsub.py:293> exception=error('nothing to repeat at position 0')>
Traceback (most recent call last):
File "C:\Users\username\AppData\Local\Programs\Python\Python310\lib\site-packages\twitchAPI\pubsub.py", line 298, in __handle_message
sub(uuid, msg_data)
File "C:\Users\username\Desktop\TwitchSounds\InProgress.py", line 34, in callback_redemptions
results = [file for file in sounds if re.search(redeemed, file)]
File "C:\Users\username\Desktop\TwitchSounds\InProgress.py", line 34, in <listcomp>
results = [file for file in sounds if re.search(redeemed, file)]
File "C:\Users\username\AppData\Local\Programs\Python\Python310\lib\re.py", line 200, in search
return _compile(pattern, flags).search(string)
File "C:\Users\username\AppData\Local\Programs\Python\Python310\lib\re.py", line 303, in _compile
p = sre_compile.compile(pattern, flags)
File "C:\Users\username\AppData\Local\Programs\Python\Python310\lib\sre_compile.py", line 788, in compile
p = sre_parse.parse(p, flags)
File "C:\Users\username\AppData\Local\Programs\Python\Python310\lib\sre_parse.py", line 955, in parse
p = _parse_sub(source, state, flags & SRE_FLAG_VERBOSE, 0)
File "C:\Users\username\AppData\Local\Programs\Python\Python310\lib\sre_parse.py", line 444, in _parse_sub
itemsappend(_parse(source, state, verbose, nested + 1,
File "C:\Users\username\AppData\Local\Programs\Python\Python310\lib\sre_parse.py", line 669, in _parse
raise source.error("nothing to repeat",
re.error: nothing to repeat at position 0
We were concerned the code with redeemed would catch EVERYTHING, but instead it catches nothing. Any ideas on how to implement this search?
If it's just a plain text search, you don't need regex or glob:
results = [file for file in sounds if redeemed in file]
No * or .* needed
If the filename is handled as a String than don't bother with the anyString+*
Just search for whatever you want to find in the string
If my sources are correct the python search() will do the trick for you
"search() functions return a Match object if they find a match of a pattern in a string....search() matches anywhere in the string"
Like this
results = [file for file in sounds if re.search(redeemed, file)]
I am using a regex and I get the error:
Traceback (most recent call last):
File "tokennet.py", line 825, in <module>
RunIt(ContentToRun,Content[0])
File "tokennet.py", line 401, in RunIt
if re.search(r'\b'+word+r'\b', str1) and re.search(r'\b'+otherWord+r'\b', str1) and word != otherWord:
File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/re.py", line 142, in search
return _compile(pattern, flags).search(string)
File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/re.py", line 242, in _compile
raise error, v # invalid expression
sre_constants.error: nothing to repeat
I've looked around, and it seems this error is associated with *, but not sure why I'm getting it. What do I have to do to str1 to stop getting it? str1 is one line in a massive text file, and when I print str1 to see what line in particular is bugging, it looks like a normal line...
I suggest you to use re.escape(word), since your variable word may contain any regex special characters. I think the error came because of special characters present inside the variable. By using re.escape(variable-name), it escapes any special characters present inside the variable.
if re.search(r'\b'+re.escape(word)+r'\b', str1) and re.search(r'\b'+re.escape(otherWord)+r'\b', str1) and word != otherWord:
When my python code tried to use simplify it shows following error. This problem showed after i run separate code file of pyparsing(Which execute successfully). The same code is working fine before.
Edit:
>>> expression="a+b+z"
>>> t=simplify(expression)
ast.py:4: SyntaxWarning: invalid pattern (**) passed to Regex
operator = pp.Regex("**").setName("operator")
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "C:\Python27\lib\site-packages\sympy\simplify\simplify.py", line 507, in simplify
expr = sympify(expr)
File "C:\Python27\lib\site-packages\sympy\core\sympify.py", line 308, in sympify
from sympy.parsing.sympy_parser import (parse_expr, TokenError,
File "C:\Python27\lib\site-packages\sympy\parsing\sympy_parser.py", line 11, in <module>
import ast
File "ast.py", line 4, in <module>
operator = pp.Regex("**").setName("operator")
File "C:\Python27\lib\site-packages\pyparsing.py", line 1920, in __init__
self.re = re.compile(self.pattern, self.flags)
File "C:\Python27\Lib\re.py", line 190, in compile
return _compile(pattern, flags)
File "C:\Python27\Lib\re.py", line 244, in _compile
raise error, v # invalid expression
sre_constants.error: nothing to repeat
Please suggest?
You have a local file, ast.py, which is getting imported in place of Python's built-in ast module. You should remove or rename this file to avoid the name conflict, as this can cause other modules to not work correctly.
Additionally, your local module contains the following line, which is causing an exception on import:
operator = pp.Regex("**").setName("operator")
** is not a valid regular expression. In a regular expression, * means "0 or more repetitions of the preceding expression", which doesn't make sense at the beginning of an expression because there is "nothing to repeat" (as the error message says).
I am using a regex and I get the error:
Traceback (most recent call last):
File "tokennet.py", line 825, in <module>
RunIt(ContentToRun,Content[0])
File "tokennet.py", line 401, in RunIt
if re.search(r'\b'+word+r'\b', str1) and re.search(r'\b'+otherWord+r'\b', str1) and word != otherWord:
File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/re.py", line 142, in search
return _compile(pattern, flags).search(string)
File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/re.py", line 242, in _compile
raise error, v # invalid expression
sre_constants.error: nothing to repeat
I've looked around, and it seems this error is associated with *, but not sure why I'm getting it. What do I have to do to str1 to stop getting it? str1 is one line in a massive text file, and when I print str1 to see what line in particular is bugging, it looks like a normal line...
I suggest you to use re.escape(word), since your variable word may contain any regex special characters. I think the error came because of special characters present inside the variable. By using re.escape(variable-name), it escapes any special characters present inside the variable.
if re.search(r'\b'+re.escape(word)+r'\b', str1) and re.search(r'\b'+re.escape(otherWord)+r'\b', str1) and word != otherWord:
I am trying this code from here docs
class Form(Form):
image = FileField(u'Image File', validators=[Regexp(u'^[^/\\]\.jpg$')])
def validate_image(form, field):
if field.data:
field.data = re.sub(r'[^a-z0-9_.-]', '_', field.data)
Here is the error:
Traceback (most recent call last):
File "tornadoexample2-1.py", line 111, in <module>
class Form(Form):
File "tornadoexample2-1.py", line 119, in Form
image = FileField(u'Image File', validators=[Regexp(u'^[^/\\]\.jpg$')])
File "/usr/local/lib/python2.7/dist-packages/wtforms/validators.py", line 256, in __init__
regex = re.compile(regex, flags)
File "/usr/lib/python2.7/re.py", line 190, in compile
return _compile(pattern, flags)
File "/usr/lib/python2.7/re.py", line 242, in _compile
raise error, v # invalid expression
sre_constants.error: unexpected end of regular expression
Any idea about what the problem?
The regexp in Regexp(u'^[^/\\]\.jpg$') is not quite good.
Try running this, you will get the same exception:
import re
re.compile(u'^[^/\\]\.jpg$')
You need to escape each \ slash twice inside the [] brackets.
So you can rewrite it as u'^[^/\\\\]\.jpg$' or as a raw string ur'^[^/\\]\.jpg$'.
Hope this helps.