I have the following python list:
original = [(7782, 'Mandarin, Chinese'),
(7783, 'Italian, Conversational Spanish'),
(7792, 'Spanish, English'),
(7793, 'English, Italian')]
What I want as result is like this:
[(7782, 'Mandarin'),
(7782, 'Chinese'),
(7783, 'Italian'),
(7783, 'Coversational Spanish'),
(7792, 'Spanish'),
(7792, 'English'),
(7793, 'English'),
(7793, 'Italian') ]
I am new to python. How can I achieve this? My code so far is like so:
import pymysql
db = pymysql.connect("localhost","root","123456","itutor" )
cursor = db.cursor()
query = "SELECT distinct user_id, language from table;"
cursor.execute(query)
r = list(cursor.fetchall())
db.close()
r2 = r[0][1].split(",")
Assuming you can't resolve the issue upstream, you can use a nested list comprehension:
res = [(num, lang) for num, languages in original for lang in languages.split(', ')]
[(7782, 'Mandarin'),
(7782, 'Chinese'),
(7783, 'Italian'),
(7783, 'Conversational Spanish'),
(7792, 'Spanish'),
(7792, 'English'),
(7793, 'English'),
(7793, 'Italian')]
To understand how this is constructed, consider the equivalent for
loop:
res = []
for num, languages in original:
for lang in languages.split(', '):
res.append((num, lang))
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