I have a list like this.
all_chords = [['C', 'C', 'E', 'G'],
['CM7', 'C', 'E', 'G', 'B'],
['C7', 'C', 'E', 'G', 'Bb'],
['Cm7', 'C', 'Eb', 'G', 'Bb'],
['Cm7b5', 'C', 'Eb', 'Gb', 'Bb'],
['Cdim7', 'C', 'Eb', 'Gb', 'Bbb(A)'],
['Caug7', 'C', 'E', 'G#', 'Bb'],
['C6', 'C', 'E', 'G', 'A'],
['Cm6', 'C', 'Eb', 'G', 'A'],
]
I want to print out to a csv file, something like this.
C_chords.csv
C;C,E,G
CM7;C,E,G,B
C7;C,E,G,Bb
Cm7;C,Eb,G,Bb
Cm7b5;C,Eb,Gb,Bb
Cdim7;C,Eb,Gb,Bbb(A)
Caug7;C,E,G#,Bb
C6;C,E,G,A
Cm6;C,Eb,G,A
It has two fileds which are separted by semicolon. (not by a comma)
I used csv module, like this.
myfile = open('C_chords.csv','w')
wr = csv.writer(myfile, quotechar=None)
wr.writerows(all_chords)
myfile.close()
The result is..
C,C,E,G
CM7,C,E,G,B
C7,C,E,G,Bb
Cm7,C,Eb,G,Bb
Cm7b5,C,Eb,Gb,Bb
Cdim7,C,Eb,Gb,Bbb(A)
Caug7,C,E,G#,Bb
C6,C,E,G,A
Cm6,C,Eb,G,A
Should I modify the list? Somewhat like this?
[['C',';', 'C', 'E', 'G'],.......]
or any other brilliant ideas do you guys have?
Thanks in advance.
You're writing four columns, not two, if you want the last list elements be one single column, you need to join them first manually.
And you need to change the delimiter if you want the csv semicolon separated, not the quote character:
import csv
all_chords = [['C', 'C', 'E', 'G'],
['CM7', 'C', 'E', 'G', 'B'],
['C7', 'C', 'E', 'G', 'Bb'],
['Cm7', 'C', 'Eb', 'G', 'Bb'],
['Cm7b5', 'C', 'Eb', 'Gb', 'Bb'],
['Cdim7', 'C', 'Eb', 'Gb', 'Bbb(A)'],
['Caug7', 'C', 'E', 'G#', 'Bb'],
['C6', 'C', 'E', 'G', 'A'],
['Cm6', 'C', 'Eb', 'G', 'A'],
]
myfile = open('C_chords.csv','w')
wr = csv.writer(myfile, delimiter=';')
wr.writerows([c[0], ','.join(c[1:])] for c in all_chords)
myfile.close()
I think it's easier to do it without the csv module:
with open('C_chords.csv','w') as out_file:
for row in all_chords:
print('{};{}'.format(row[0], ','.join(row[1:])), file=out_file)
Related
I 'm a Python beginner, I have a list that needs to be converted to json format.
I hope to get some help.
raw data：
result = [('A', 'a1', '1'),
('A', 'a2', '2'),
('B', 'b1', '1'),
('B', 'b2', '2')]
The result I want：
[{'type':'A',
'data':[{'name':'a1','url':'1'},
{'name':'a2','url':'2'}]
},
{'type': 'B',
'data': [{'name':'b1', 'url': '1'},
{'name':'b2','url':'2'}]
}]
('A', 'a1', 1) is an example of a tuple, which are iterable.
result = [('A', 'a1', '1'),
('A', 'a2', '2'),
('B', 'b1', '1'),
('B', 'b2', '2')]
type_list = []
for tup in result:
if len(type_list) == 0:
type_list.append({'type': tup[0], 'data': [{ 'name': tup[1], 'url': tup[2] }]})
else:
for type_obj in type_list:
found = False
if type_obj['type'] == tup[0]:
type_obj['data'].append({ 'name': tup[1], 'url': tup[2] })
found = True
break
if not found:
type_list.append({'type': tup[0], 'data': [{ 'name': tup[1], 'url': tup[2] }]})
print(type_list)
which prints:
[{'type': 'A', 'data': [{'name': 'a1', 'url': '1'}, {'name': 'a2', 'url': '2'}]}, {'type': 'B', 'data': [{'name': 'b1', 'url': '1'}, {'name': 'b2', 'url': '2'}]}]
I have a several mySQL tables where I have saved the relation ID of the child table comma separated. Now I have to transfer this entries into a new table where for each relation is one entry.
Is there an easy way to transfer import query into the correct format?
Here the data example, my old table (cat_projects) has the following entries I want convert:
-- export of table cat_projects
INSERT INTO `cat_projects` (`id`, `authors`) VALUES
(2, '4,1'),
(3, '0'),
(4, '8,4,1'),
(5, '13,12'),
(10, '19,4,1'),
(13, ''),
(14, ''),
(15, '28,27,25,12,9,1');
This entries I want just to write into the new relation table (cat_project_relation). The att_id links to the another table where I have save the settings of the old authors column:
-- att_id = 58
-- item_id = id
-- value_sorting = counting from 0 for each item_id
-- value_id = for each relation one entry value
INSERT INTO `cat_project_relation` (`att_id`, `item_id`, `value_sorting`, `value_id`) VALUES
(58, 2, 0, '4'),
(58, 2, 1, '1'),
(58, 3, 0, '0'),
(58, 4, 0, '8'),
(58, 4, 1, '4'),
(58, 4, 2, '1'),
(58, 5, 0, '13'),
(58, 5, 1, '12'),
(58, 10, 0, '19'),
(58, 10, 1, '4'),
(58, 10, 2, '1'),
(58, 13, 0, ''),
(58, 14, 0, ''),
(58, 15, 0, '28'),
(58, 15, 1, '27'),
(58, 15, 2, '25'),
(58, 15, 3, '12'),
(58, 15, 4, '9'),
(58, 15, 5, '1');
I hope it is clear what I try to achieve. Is it possible to do that directly in SQL or do I have to apply an external bash script?
Actually it wasn't as difficult as I thought to write a little bash script. And I guess its the easier solution then program something in SQL.
#!/bin/bash
# input table
table="(2, '4,1'),
(3, '0'),
(4, '8,4,1'),
(5, '13,12'),
(10, '19,4,1'),
(13, ''),
(14, ''),
(15, '28,27,25,12,9,1');"
# fixed attribute id
att_id=58
# read each line into an array
readarray -t y <<<"$table"
# for each array item (each line)
for (( i=0; i<${#y[*]}; i=i+1 ))
do
z=${y[$i]}
# split by comma into array
IFS=', ' read -r -a array <<< "$z"
# loop through each value
for (( j=0; j<${#array[*]}; j=j+1 ))
do
# remove all other characters then number
nr=$(echo ${array[$j]} | sed 's/[^0-9]*//g')
# each first value is the item_id
if [ $j -eq 0 ]
then
item_id=$nr
else
k=$(expr $j - 1)
value_id=$nr
# print output line by line
echo "($att_id, $item_id, $k, '$value_id')," >> output.txt
fi
done
done
The result will be as the on asked in the question.
Am trying to build an multi-row insert query using Knex.js
My post request contains a variable which is formatted in the following format : [{addon_name:'sugar'},{addon_name:'milk'}]
My DB table has only one column namely addon_name
My knex query in my node application goes as follows
knex(`<table_name>`).insert(req.body.`<param_name>`))
expected op
insert into `<tablename>`(`addon_name`) values (sugar), (milk);
but the code dosn't work. Any comments ?
Error Details
{ [Error: insert into `table_name` (`0`, `1`, `10`, `11`, `12`, `13`, `14`, `15`, `16`, `17`, `18`, `19`, `2`, `20`, `21`, `22`, `23`, `24`, `25`, `26`, `27`, `28`, `29`, `3`, `30`, `31`, `32`, `33`, `34`, `35`, `36`, `37`, `38`, `39`, `4`, `40`, `41`, `5`, `6`, `7`, `8`, `9`) values ('[', '{', 'm', 'e', ':', '\'', 's', 'u', 'g', 'a', 'r', '\'', 'a', '}', ',', '{', 'a', 'd', 'd', 'o', 'n', '_', 'n', 'd', 'a', 'm', 'e', ':', '\'', 'm', 'i', 'l', 'k', '\'', 'd', '}', ']', 'o', 'n', '_', 'n', 'a') - ER_BAD_FIELD_ERROR: Unknown column '0' in 'field list']
code: 'ER_BAD_FIELD_ERROR',
errno: 1054,
sqlState: '42S22',
index: 0 }
Though this is an old question, I am replying here just for others who stumble upon this.
Knex now supports multi-row inserts like this:
knex('coords').insert([{x: 20}, {y: 30}, {x: 10, y: 20}])
outputs:
insert into `coords` (`x`, `y`) values (20, DEFAULT), (DEFAULT, 30), (10, 20)
There's also the batchInsert utility will inserts a batch of rows wrapped inside a transaction.
req.body.<param_name> is always a string. Most probably this will work for you:
knex(table_name).insert(JSON.parse(req.body.param_name)));
What you are seeing in your error is Knex treating the string as an array of chars, trying to push it to the table.
In the error, the following:
values ('[', '{', 'm', 'e', ':', '\'', 's', ...
Is actually your string being broken down: [{me:\'s....
Thanks. I changed the structure of my input in post method, to an comma separated string. That way it gets easier to parse the input and model it the way I need.
post method input : "milk,sugar"
code
//Knex accepts multi row insert in the following format [{},{}] => we need to
//model our input that way
var parsedValues = [];
try {
var arr = req.body.addons.split(',');
}catch(err){
return res.send({ "Message": "405" }); // Data not sent in proper format
}
for (var i in arr) {
parsedValues.push({addon_name: arr[i]});
}
console.log(parsedValues);
knex(`<table_name>`).insert(parsedValues).then(function (rows){
console.log(rows);
return res.send({ "Message": "777" }); // Operation Success
}).catch(function (err){
console.log(err)
return res.send({ "Message": "403" }); // PK / FK Violation
});
You can use batch insert
DB.transaction(async (t: Knex.Transaction) => {
return await t
.batchInsert("addon_name", addon_nameRecords)
.returning("id");
});
To remind you, tr
reads a byte stream from its standard input and writes the result to
the standard output. As arguments, it takes two sets of characters
(generally of the same length), and replaces occurrences of the
characters in the first set with the corresponding elements from the
second set. -- Wikipedia
I need to this within the context of an UPDATE statement and, ideally, without doing 26 nested REPLACE function calls.
EDIT:
For you nosy-Parkers who just have to know what I'm doing: I want to make the in-database equivalent of upsidedowntext.com. Right now, I do this:
SELECT
REVERSE(
REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(UPPER(value),
'A', 'ɐ'),
'B', 'q'),
'C', 'ɔ'),
'D', 'p'),
'E', 'ǝ'),
'F', 'ɟ'),
'G', 'b'),
'H', 'ɥ'),
'I', 'ı'),
'J', 'ظ'),
'K', 'ʞ'),
'L', 'ן'),
'M', 'ɯ'),
'N', 'u'),
'O', 'o'),
'P', 'd'),
'Q', 'b'),
'R', 'ɹ'),
'S', 's'),
'T', 'ʇ'),
'U', 'n'),
'V', 'ʌ'),
'W', 'ʍ'),
'X', 'x'),
'Y', 'ʎ'),
'Z', 'z')) from table;
I have to compare two string fields containing letters but not alphabetically.
I want to compare them according to this order :
"J" "L" "M" "N" "P" "Q" "R" "S" "T" "H" "V" "W" "Y" "Z"
So if I compare H with T, H will be greater than T (unlike alphabetically)
And if I test if a value is greater than 'H' (> 'H') I will get all the entries containing the values ("V" "W" "Y" "Z") (again, unlike alphabetical order)
How can I achieve this in one SQL query?
Thanks
SELECT *
FROM yourtable
WHERE
FIELD(col, 'J', 'L', 'M', 'N', 'P', 'Q', 'R', 'S', 'T', 'H', 'V', 'W', 'Y', 'Z') >
FIELD('H', 'J', 'L', 'M', 'N', 'P', 'Q', 'R', 'S', 'T', 'H', 'V', 'W', 'Y', 'Z')
^ your value
Or also:
SELECT *
FROM yourtable
WHERE
LOCATE(col, 'JLMNPQRSTHVWYZ')>
LOCATE('H', 'JLMNPQRSTHVWYZ')
Please see fiddle here.
You can do
SELECT ... FROM ... ORDER BY yourletterfield='J' DESC, yourletterfield='L' DESC, yourletterfield='M' DESC, ...
The equality operator will evaluate to "1" when it's true, "0" when false, so this should give you the desired order.
There's actually a FIELD() function that will make this a bit less verbose. See this article for details.
SELECT ... FROM ... ORDER BY FIELD(yourletterfield, 'J', 'L', 'M', ...)