Ticket #12341: trac_12341.patch

sage/databases/cremona.py

@@ -52 +52 @@
 
 import sage.schemes.elliptic_curves.constructor as elliptic
 from sql_db import SQLDatabase, verify_column
-from sage.misc.package import optional_packages
+from sage.misc.package import is_package_installed
 from sage.misc.misc import SAGE_SHARE, walltime
 
 import re
@@ -114 +114 @@
 
         sage: d = sage.databases.cremona.build('cremona','ecdata.tgz')   # not tested
     """
-    t = name.replace(' ','_')
-    if os.path.exists("%s/cremona/%s.db"%(SAGE_SHARE, t)):
-        raise RuntimeError("Please (re)move %s/cremona/%s.db"%(SAGE_SHARE, t)
-        + " before rebuilding database.")
+    db_path = os.path.join(SAGE_SHARE,'cremona',name.replace(' ','_')+'.db')
+    if os.path.exists(db_path):
+        raise RuntimeError('Please (re)move %s before building '%db_path \
+                + 'database')
     if not os.path.exists(data_tgz):
         raise IOError, "The data file is not at %s"%data_tgz
     t = walltime()
@@ -584 +584 @@
             sage: c.name
             'cremona mini'
         """
+        self.name = name
+        name = name.replace(' ','_')
+        db_path = os.path.join(SAGE_SHARE, 'cremona', name+'.db')
         if build:
             if name is None:
                 raise RuntimeError('The database must have a name.')
             if read_only:
                 raise RuntimeError('The database must not be read_only.')
-            self.name = name
-            name = name.replace(' ','_')
-            SQLDatabase.__init__(self, '%s/cremona/%s.db'%(SAGE_SHARE, name), \
-                read_only=read_only, skeleton=_miniCremonaSkeleton)
+            SQLDatabase.__init__(self, db_path, read_only=read_only, \
+                    skeleton=_miniCremonaSkeleton)
             return
-        self.name = name
-        name = name.replace(' ','_')
-        SQLDatabase.__init__(self, '%s/cremona/%s.db'%(SAGE_SHARE, name), \
-            read_only=read_only)
+        if not os.path.isfile(db_path):
+            raise ValueError("Desired database (='%s') does not "%self.name \
+                    + "exist")
+        SQLDatabase.__init__(self, db_path, read_only=read_only)
         if self.get_skeleton() != _miniCremonaSkeleton:
             raise RuntimeError('Database at %s does '%(self.__dblocation__) \
               + 'not appear to be a valid SQL Cremona database.')
@@ -854 +855 @@
             if N < self.largest_conductor():
                 message = "There is no elliptic curve with label " + label \
                     + " in the database (note: use lower case letters!)"
-            elif 'database_cremona_ellcurve' in \
-                    [s.split('-')[0] for s in optional_packages()[0]]:
+            elif is_package_installed('database_cremona_ellcurve'):
                 message = "There is no elliptic curve with label " + label \
                     + " in the currently available databases"
             else:
@@ -1306 +1306 @@
             sage: c.name                                              # optional - database_cremona_ellcurve
             'cremona'
         """
+        self.name = name
+        name = name.replace(' ','_')
+        db_path = os.path.join(SAGE_SHARE, 'cremona', name+'.db')
         if build:
             if name is None:
                 raise RuntimeError('The database must have a name.')
             if read_only:
                 raise RuntimeError('The database must not be read_only.')
-            self.name = name
-            name = name.replace(' ','_')
-            SQLDatabase.__init__(self, '%s/cremona/%s.db'%(SAGE_SHARE, name), \
-                read_only=read_only, skeleton=_cremonaSkeleton)
+            SQLDatabase.__init__(self, db_path, read_only=read_only, \
+                    skeleton=_cremonaSkeleton)
             return
-        self.name = name
-        name = name.replace(' ','_')
-        SQLDatabase.__init__(self, '%s/cremona/%s.db'%(SAGE_SHARE, name), \
-            read_only=read_only)
+        if not os.path.isfile(db_path):
+            raise ValueError("Desired database (='%s') does not "%self.name \
+                    + "exist")
+        SQLDatabase.__init__(self, db_path, read_only=read_only)
         if self.get_skeleton() != _cremonaSkeleton:
             raise RuntimeError('Database at %s does '%(self.__dblocation__) \
               + 'not appear to be a valid SQL Cremona database.')
@@ -1542 +1543 @@
         True
         sage: isinstance(c, sage.databases.cremona.LargeCremonaDatabase)  # optional - database_cremona_ellcurve
         True
+
+    Verify that ticket #12341 has been resolved::
+
+        sage: c = CremonaDatabase('should not exist',mini=True)
+        Traceback (most recent call last):
+        ...
+        ValueError: Desired database (='should not exist') does not exist
+        sage: c = CremonaDatabase('should not exist',mini=False)
+        Traceback (most recent call last):
+        ...
+        ValueError: Desired database (='should not exist') does not exist
+        sage: from sage.misc.misc import SAGE_SHARE
+        sage: os.path.isfile(os.path.join(SAGE_SHARE,'cremona','should_not_exist.db'))
+        False
     """
     global _db
     if set_global is None:
@@ -1549 +1564 @@
     if name is None and not set_global:
         return _db
     if set_global and name is None:
-        if os.path.isfile('%s/cremona/cremona.db'%SAGE_SHARE):
+        if is_package_installed('database_cremona_ellcurve'):
             name = 'cremona'
-        elif os.path.isfile('%s/cremona/cremona_mini.db'%SAGE_SHARE):
+        else:
             name = 'cremona mini'
-        else:
-            raise RuntimeError('Could not find valid cremona database. ' \
-                + 'Please make sure SAGE_SHARE is set correctly.')
     if name == 'cremona':
         mini = False
     elif name == 'cremona mini':

sage/schemes/elliptic_curves/ell_curve_isogeny.py

@@ -528 +528 @@
         x
         sage: phi.rational_maps()
         ((x^2 + 1)/x, (x^2*y - y)/x^2)
-        sage: phi == loads(dumps(phi))   # optional - pickling http://trac.sagemath.org/sage_trac/ticket/11599
+        sage: phi == loads(dumps(phi))   # not tested - pickling http://trac.sagemath.org/sage_trac/ticket/11599
         True
 
     A more complicated example of a characteristic 2 field::

sage/schemes/elliptic_curves/ell_torsion.py

@@ -155 +155 @@
             sage: type(T)
             <class 'sage.schemes.elliptic_curves.ell_torsion.EllipticCurveTorsionSubgroup_with_category'>
 
-            sage: T == loads(dumps(T))  # optional - pickling http://trac.sagemath.org/sage_trac/ticket/11599
+            sage: T == loads(dumps(T))  # not tested - pickling http://trac.sagemath.org/sage_trac/ticket/11599
             True
 
         """

sage/schemes/elliptic_curves/lseries_ell.py

@@ -161 +161 @@
 
         EXAMPLES:
             sage: E = EllipticCurve('37a')
-            sage: a = E.lseries().sympow(2,16)   # optional - requires precomputing "sympow('-new_data 2')"
-            sage: a      # optional
+            sage: a = E.lseries().sympow(2,16)   # not tested - requires precomputing "sympow('-new_data 2')"
+            sage: a                              # not tested
             '2.492262044273650E+00'
-            sage: RR(a)                      # optional
+            sage: RR(a)                          # not tested
             2.49226204427365
         """
         from sage.lfunctions.sympow import sympow
@@ -190 +190 @@
 
         EXAMPLES:
             sage: E = EllipticCurve('37a')
-            sage: print E.lseries().sympow_derivs(1,16,2)      # optional -- requires precomputing "sympow('-new_data 2')"
+            sage: print E.lseries().sympow_derivs(1,16,2)      # not tested -- requires precomputing "sympow('-new_data 2')"
             sympow 1.018 RELEASE  (c) Mark Watkins --- see README and COPYING for details
             Minimal model of curve  is [0,0,1,-1,0]
             At 37: Inertia Group is  C1 MULTIPLICATIVE REDUCTION

sage/schemes/elliptic_curves/padic_lseries.py

@@ -839 +839 @@
             sage: lp = E.padic_lseries(3)
             sage: lp.series(2,quadratic_twist=-19)
             2 + 2*3 + 2*3^2 + O(3^4) + (1 + O(3))*T + (1 + O(3))*T^2 + O(T^3)
-            sage: E.quadratic_twist(-19).label()    #optional --- conductor is greater than 10000
+            sage: E.quadratic_twist(-19).label()    # optional -- database_cremona_ellcurve
             '15523a1'
         
         This proves that the rank of '15523a1' is zero, even if ``mwrank`` can not determine this.