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).
Related
I am using the PyYAML-3.10 as part of a Python program on macOS 10, using Python version 2.7.10. I am not able to make sense of these compilation errors. Since PyYAML-3.10 is a stable version of PyYAML, it should give no compilation errors. The errors are listed below. Any suggestions would be appreciated.
File "pyR#TE.py", line 3, in <module>
import yaml
File "/Users/PyR#TE/pyrate-1.0.0/yaml/__init__.py", line 8, in <module>
from .loader import *
File "/Users/PyR#TE/pyrate-1.0.0/yaml/loader.py", line 4, in <module>
from .reader import *
File "/Users/PyR#TE/pyrate-1.0.0/yaml/reader.py", line 45, in <module>
class Reader(object):
File "/Users/PyR#TE/pyrate-1.0.0/yaml/reader.py", line 137, in Reader
NON_PRINTABLE = re.compile('[^\x09\x0A\x0D\x20-\x7E\x85\xA0-\uD7FF\uE000-\uFFFD]')
raise error, v # invalid expression
sre_constants.error: bad character range
It seems that PyYAMP-3.10 is not compatible with Python 2. (Did you mean "PyYAML", by the way? I could not find a reference to a "PyYAMP" package anywhere.) The compilation error you are seeing is from re.compile - when Python is trying to compile a regular expression.
I tried using the line in your error message containing re.compile in Python 2 and Python 3.
Python 2:
>>> import re
>>> re.compile('[^\x09\x0A\x0D\x20-\x7E\x85\xA0-\uD7FF\uE000-\uFFFD]')
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/lib/python2.7/re.py", line 194, in compile
return _compile(pattern, flags)
File "/usr/lib/python2.7/re.py", line 251, in _compile
raise error, v # invalid expression
sre_constants.error: bad character range
>>>
Python 3:
>>> import re
>>> re.compile('[^\x09\x0A\x0D\x20-\x7E\x85\xA0-\uD7FF\uE000-\uFFFD]')
re.compile('[^\t\n\r -~\x85\xa0-\ud7ff\ue000-�]')
>>>
So your options are either to find a package that supports Python 2, or to upgrade your code to Python 3. I recommend upgrading, as Python 2 is no longer supported.
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")
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.
trying to get a 'sed replace' function in python working
What I have now
def pysed(filename,search,replace):
for line in fileinput.input(filename,inplace=True):
sys.stdout.write(re.sub(r'{0}','{1}',line.format(search,replace)))
calling the function...
pysed('/dev/shm/FOOD_DES.txt','Butter','NEVER')
File /dev/shm/FOOD_DES.txt contains the following....
~01001~^~0100~^~Butter, salted~^~BUTTER,WITH SALT~^~~^~~^~Y~^~~^0^~~^6.38^4.27^8.79^3.87
~01002~^~0100~^~Butter, whipped, with salt~^~BUTTER,WHIPPED,WITH SALT~^~~^~~^~Y~^~~^0^~~^6.38^4.27^8.79^3.87
~01003~^~0100~^~Butter oil, anhydrous~^~BUTTER OIL,ANHYDROUS~^~~^~~^~Y~^~~^0^~~^6.38^4.27^8.79^3.87
~01004~^~0100~^~Cheese, blue~^~CHEESE,BLUE~^~~^~~^~Y~^~~^0^~~^6.38^4.27^8.79^3.87
~01005~^~0100~^~Cheese, brick~^~CHEESE,BRICK~^~~^~~^~Y~^~~^0^~~^6.38^4.27^8.79^3.87
~01006~^~0100~^~Cheese, brie~^~CHEESE,BRIE~^~~^~~^~Y~^~~^0^~~^6.38^4.27^8.79^3.87
~01007~^~0100~^~Cheese, camembert~^~CHEESE,CAMEMBERT~^~~^~~^~Y~^~~^0^~~^6.38^4.27^8.79^3.87
~01008~^~0100~^~Cheese, caraway~^~CHEESE,CARAWAY~^~~^~~^~~^~~^0^~~^6.38^4.27^8.79^3.87
~01009~^~0100~^~Cheese, cheddar~^~CHEESE,CHEDDAR~^~~^~~^~Y~^~~^0^~~^6.38^4.27^8.79^3.87
~01010~^~0100~^~Cheese, cheshire~^~CHEESE,CHESHIRE~^~~^~~^~~^~~^0^~~^6.38^4.27^8.79^3.87
When running this however, I am getting the following error. Any thoughts, ideas?
pysed('/dev/shm/FOOD_DES.txt','Butter','NEVER')
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "<stdin>", line 3, in pysed
File "/usr/lib64/python2.6/re.py", line 151, in sub
return _compile(pattern, 0).sub(repl, string, count)
File "/usr/lib64/python2.6/re.py", line 245, in _compile
raise error, v # invalid expression
You wrote:
sys.stdout.write(re.sub(r'{0}','{1}',line.format(search,replace)))
This is rather confusing. Is this what you meant to write?
sys.stdout.write(re.sub('{0}'.format(search), '{0}'.format(replace), line))
That would of course be equivalent to:
sys.stdout.write(re.sub(search, replace, line))