pythoncassandracqlshccm

Unable to launch "Python cqlsh" - ValueError: RE flag setting not allowed in SaferScanner lexicon (0b110010)


Cassandra Version 2.1.1

Python Version 3.8

Using CCM to run 3 virtual Cassandra nodes on a single machine.

While running cqlsh : Getting the below stack trace.

C:\Users\manjr\.ccm\repository\2.1.1\bin>python cqlsh
cqlsh:491: SyntaxWarning: "is not" with a literal. Did you mean "!="?
  if custom_prompt is not '':
Traceback (most recent call last):
  File "cqlsh", line 120, in <module>
    from cqlshlib import cqlhandling, cql3handling, pylexotron, sslhandling, async_insert, meter
  File "C:\Users\manjr\.ccm\repository\2.1.1\bin\..\pylib\cqlshlib\cqlhandling.py", line 21, in <module>
    from . import pylexotron, util
  File "C:\Users\manjr\.ccm\repository\2.1.1\bin\..\pylib\cqlshlib\pylexotron.py", line 304, in <module>
    class ParsingRuleSet:
  File "C:\Users\manjr\.ccm\repository\2.1.1\bin\..\pylib\cqlshlib\pylexotron.py", line 305, in ParsingRuleSet
    RuleSpecScanner = SaferScanner([
  File "C:\Users\manjr\.ccm\repository\2.1.1\bin\..\pylib\cqlshlib\saferscanner.py", line 32, in __init__
    (SUBPATTERN, (len(p)+1, self.subpat(phrase, flags))),
  File "C:\Users\manjr\.ccm\repository\2.1.1\bin\..\pylib\cqlshlib\saferscanner.py", line 41, in subpat
    return cls.scrub_sub(re.sre_parse.parse(phrase, flags), flags)
  File "C:\Users\manjr\.ccm\repository\2.1.1\bin\..\pylib\cqlshlib\saferscanner.py", line 59, in scrub_sub
    raise ValueError("RE flag setting not allowed in SaferScanner lexicon (%s)" % (bin(sub.state.flags),))
ValueError: RE flag setting not allowed in SaferScanner lexicon (0b110010)

Solution

  • Cassandra 2.1.1 doesn't support Python 3.x at all. You need to have Python 2 installed to make it running. Python 3 is supported only in upcoming 4.0. Support for Python 3 in Cassandra 3.x is only planned (see CASSANDRA-16403)