I am executing a mysql query in python using the MySQLdb package. The code looks something like this:
c=db.cursor()
c.execute("""select * from table""")
output = []
for row in c:
output.append(row[4])
where row[4]
contains a decimal value that I want to store in the output
list.
The problem is every value that I am getting looks like this: Decimal('XX.XX')
where all I want in the output
list is XX.XX. At the end of the script, my output
list looks like this:
[Decimal('10.02'), Decimal('20.24'), ...]
But I need it to just contain the numbers, like this:
[10.02, 20.24, ...]
How do I do that?
Thanks!
c=db.cursor()
c.execute("""select * from table""")
output = []
for row in c:
output.append(float(row[4]))
Use float()
:
output.append(float(row[4]))
But float()
can result in something like:
In [184]: float(Decimal('10.02'))
Out[184]: 10.02
In [185]: float(Decimal('20.24'))
Out[185]: 20.239999999999998
If you are trying to write a generic code that operates on the column output, the above solution won't workout. In that case we can write our SELECT
query in a way that the column in returned as String and we just get the value of what we want.
The query can be framed in below way,
SELECT
CAST(COL1 AS CHAR) AS COL1,
CAST(COL2 AS CHAR) AS COL2,
.
.
.
FROM TABLE;
from decimal import Decimal
c=db.cursor()
c.execute("""select * from table""")
output = []
for row in c:
row_data = []
for data in row:
if type(data) is Decimal:
row_data.append(float(data))
else:
row_data.append(str(dat))
output.append(row_data)
;)
来源:https://stackoverflow.com/questions/12661999/get-raw-decimal-value-from-mysqldb-query