1 """

     2 Extracts the version of the PostgreSQL server.

     3 """

     4 

     5 import re

     6 

     7 # This reg-exp is intentionally fairly flexible here.

     8 # Needs to be able to handle stuff like:

     9 #   PostgreSQL 8.3.6

    10 #   EnterpriseDB 8.3

    11 #   PostgreSQL 8.3 beta4

    12 #   PostgreSQL 8.4beta1

    13 VERSION_RE = re.compile(r'\S+ (\d+)\.(\d+)\.?(\d+)?')

    14 

    15 def _parse_version(text):

    16     "Internal parsing method. Factored out for testing purposes."

    17     major, major2, minor = VERSION_RE.search(text).groups()

    18     try:

    19         return int(major), int(major2), int(minor)

    20     except (ValueError, TypeError):

    21         return int(major), int(major2), None

    22 

    23 def get_version(cursor):

    24     """

    25     Returns a tuple representing the major, minor and revision number of the

    26     server. For example, (7, 4, 1) or (8, 3, 4). The revision number will be

    27     None in the case of initial releases (e.g., 'PostgreSQL 8.3') or in the

    28     case of beta and prereleases ('PostgreSQL 8.4beta1').

    29     """

    30     cursor.execute("SELECT version()")

    31     return _parse_version(cursor.fetchone()[0])