SQL.py

import sqlite3,sys
def convert(value):
    if value.startswith('~'):
        return value.strip('~')
    if not value:
        value=''
    return float(value)
conn=sqlite3.connect('food.db')
curs=conn.cursor()
curs.execute('''
CREATE TABLE IF NOT EXISTS food(
id      TEXT    PRIMARY KEY,
desc    TEXT,
water   FLOAT,
fat     FLOAT,
fiber   FLOAT,
sugar   FLOAT
)
''')
insert_query='INSERT INTO food VALUES(?,?,?,?,?,?)'
for line in open('ABBREV.txt'):
    fields=line.split('^')
    field_count=len(fields)
    print(fields)
    vals=[convert(f) for f in fields[:field_count]]
    curs.execute(insert_query,vals)
conn.commit()

select_all='SELECT * FROM food'
curs.execute(select_all)
print(curs.fetchall())

select_str='fat<=100 AND fiber>=10 AND sugar ORDER BY sugar'
try:
    if sys.argv[1]: select_str=sys.argv[1]
    print('\n',sys.argv,'\n')
except: pass
#命令行调用,windows下SQL.py要加引号
#python SQL.py 'fat<=100 AND fiber>=10 AND sugar ORDER BY sugar'
print(select_str)
select_query='SELECT * FROM food WHERE %s' % select_str
curs.execute(select_query)
names=[f[0] for f in curs.description]
name=[f for f in curs.description]
print(name)
for row in curs.fetchall():
    for pair in zip(names,row):
        print('%s:%s' % pair)
conn.close()