I have created a database table called fruits with 3 columns, id(int primary key), fruits(text) and weight(float).

How do I create a dictionary and add all the fruits and weight as key-value pairs to the dictionary?

import sqlite3

conn = sqlite3.connect("database.db")

sql = """SELECT fruit,weight FROM fruits"""

cursor = conn.execute(sql)
data = cursor.fetchall()

fruitweight= {}
i = 0

while(i < len(data)):
    fruitweight['<fruitname>'] = <fruitweight>
    i = i 1

CodePudding user response：

Something like this:

for row in data:
    name, weight = row
    fruitweight[name] = weight

fetchall() returns a list of tuples of values from the database according to your query. The above unpacks the tuples into two variables.

If you want to get fancy, you can use a dictionary comprehension with tuple unpacking:

fruitweight = {name: weight for name, weight in data}

And finally, execute() actually returns a cursor that you can iterate over, so I think your code can be reduced to the following:

import sqlite3

conn = sqlite3.connect("database.db")

sql = """SELECT fruit,weight FROM fruits"""
fruitweight = {name: weight for name, weight in conn.execute(sql)}

CodePudding user response：

I don't think that the cursor is correct but you should use for loop instead:

import sqlite3

conn = sqlite3.connect("database.db")
cur = conn.cursor()

sql = """SELECT fruit,weight FROM fruits"""

cur.execute(sql)
data = cur.fetchall()


fruitweight= {}

for i in data:
    fruitweight[i[0]] = i[1]

conn.close()

print(fruitweight)

CodePudding user response：

You could do it like this:

import sqlite3

with sqlite3.connect('/Users/andy/andy') as conn:
    cursor = conn.execute('select fruit, weight from fruits')
    D = dict()
    for row in cursor.fetchall():
        D[row[0]] = row[1]
    print(D)