[Python编程(第4版)].(Programming.Python.4th.Edition).Mark.Lutz.文字版

>>> curs.execute('select * from people')

>>> colnames = [desc[0] for desc in curs.description]

>>> colnames

['name', 'job', 'pay']

>>> for row in curs.fetchall():

... for name, value in zip(colnames, row):

... print(name, '\t=>', value)

... print()

...

name => Sue

job => mus

pay => 70000

name => Ann

job => mus

pay => 65000

name => Kim

job => adm

pay => 65000

Notice how a tab character is used to try to make this output align; a better approach
might be to determine the maximum field name length (we’ll see how in a later
example).

Record dictionaries construction

It’s a minor extension of our formatted display code to create a dictionary for each
record, with field names for keys—we just need to fill in the dictionary as we go:

>>> curs.execute('select * from people')

>>> colnames = [desc[0] for desc in curs.description]

>>> rowdicts = []

>>> for row in curs.fetchall():

... newdict = {}

... for name, val in zip(colnames, row):

... newdict[name] = val

... rowdicts.append(newdict)

...

>>> for row in rowdicts: print(row)

...

{'pay': 70000, 'job': 'mus', 'name': 'Sue'}

{'pay': 65000, 'job': 'mus', 'name': 'Ann'}

{'pay': 65000, 'job': 'adm', 'name': 'Kim'}

Because this is Python, though, there are more powerful ways to build up these record
dictionaries. For instance, the dictionary constructor call accepts the zipped name/
value pairs to fill out the dictionaries for us:

>>> curs.execute('select * from people')

>>> colnames = [desc[0] for desc in curs.description]

>>> rowdicts = []

>>> for row in curs.fetchall():

... rowdicts.append( dict(zip(colnames, row)) )

1340 | Chapter 17: Databases and Persistence