PyMongo: How to use a list as a projection in find()
Let's say I have a collection coll and I want to retrieve two fields from this collection using the find() function from the PyMongo library. Let's call these fields field_1 and field_2.
The standard way to do it is:
coll.find(, 'field_1': 1, 'field_2': 1)
Now, I have these fields in a list fields_list. Is it possible to do something like:
coll.find(, fields_list)
I can't find any information in the official documentation and I doubt I'm the first one to think about doing that.
My first guess was to go through the list and create a long string: "field_1: 1, field_2: 1" but this obviously doesn't work because the colon and the "1" shouldn't be in the string for the find() function to understand the query.
Does anyone have any clue on how to use a list in the projection query?
python mongodb pymongo
asked Nov 13 '18 at 9:55
Dust009Dust009
1057
add a comment |
Let's say I have a collection coll and I want to retrieve two fields from this collection using the find() function from the PyMongo library. Let's call these fields field_1 and field_2.
The standard way to do it is:
coll.find(, 'field_1': 1, 'field_2': 1)
Now, I have these fields in a list fields_list. Is it possible to do something like:
coll.find(, fields_list)
I can't find any information in the official documentation and I doubt I'm the first one to think about doing that.
My first guess was to go through the list and create a long string: "field_1: 1, field_2: 1" but this obviously doesn't work because the colon and the "1" shouldn't be in the string for the find() function to understand the query.
Does anyone have any clue on how to use a list in the projection query?
python mongodb pymongo
asked Nov 13 '18 at 9:55
Dust009Dust009
1057
add a comment |
Let's say I have a collection coll and I want to retrieve two fields from this collection using the find() function from the PyMongo library. Let's call these fields field_1 and field_2.
The standard way to do it is:
coll.find(, 'field_1': 1, 'field_2': 1)
Now, I have these fields in a list fields_list. Is it possible to do something like:
coll.find(, fields_list)
I can't find any information in the official documentation and I doubt I'm the first one to think about doing that.
My first guess was to go through the list and create a long string: "field_1: 1, field_2: 1" but this obviously doesn't work because the colon and the "1" shouldn't be in the string for the find() function to understand the query.
Does anyone have any clue on how to use a list in the projection query?
python mongodb pymongo
asked Nov 13 '18 at 9:55
Dust009Dust009
1057
Let's say I have a collection coll and I want to retrieve two fields from this collection using the find() function from the PyMongo library. Let's call these fields field_1 and field_2.
The standard way to do it is:
coll.find(, 'field_1': 1, 'field_2': 1)
Now, I have these fields in a list fields_list. Is it possible to do something like:
coll.find(, fields_list)
I can't find any information in the official documentation and I doubt I'm the first one to think about doing that.
My first guess was to go through the list and create a long string: "field_1: 1, field_2: 1" but this obviously doesn't work because the colon and the "1" shouldn't be in the string for the find() function to understand the query.
Does anyone have any clue on how to use a list in the projection query?
python mongodb pymongo
python mongodb pymongo
asked Nov 13 '18 at 9:55
Dust009Dust009
1057
asked Nov 13 '18 at 9:55
Dust009Dust009
1057
asked Nov 13 '18 at 9:55
Dust009Dust009
1057
asked Nov 13 '18 at 9:55
Dust009Dust009
1057
asked Nov 13 '18 at 9:55
Dust009Dust009
1057
1057
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
You can try converting the field list to a dict like this:
coll.find(, field: 1 for field in field_list)
answered Nov 13 '18 at 10:22
lee-pai-longlee-pai-long
84359
Thanks, it works perfectly!
– Dust009
Nov 13 '18 at 10:29
add a comment |
Your Answer
StackExchange.ifUsing("editor", function ()
StackExchange.using("externalEditor", function ()
StackExchange.using("snippets", function ()
StackExchange.snippets.init();
);
);
, "code-snippets");
StackExchange.ready(function()
var channelOptions =
tags: "".split(" "),
id: "1"
;
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function()
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled)
StackExchange.using("snippets", function()
createEditor();
);
else
createEditor();
);
function createEditor()
StackExchange.prepareEditor(
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader:
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
,
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
);
);
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53278292%2fpymongo-how-to-use-a-list-as-a-projection-in-find%23new-answer', 'question_page');
);
Post as a guest
Required, but never shown
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
You can try converting the field list to a dict like this:
coll.find(, field: 1 for field in field_list)
answered Nov 13 '18 at 10:22
lee-pai-longlee-pai-long
84359
Thanks, it works perfectly!
– Dust009
Nov 13 '18 at 10:29
add a comment |
You can try converting the field list to a dict like this:
coll.find(, field: 1 for field in field_list)
answered Nov 13 '18 at 10:22
lee-pai-longlee-pai-long
84359
Thanks, it works perfectly!
– Dust009
Nov 13 '18 at 10:29
add a comment |
You can try converting the field list to a dict like this:
coll.find(, field: 1 for field in field_list)
answered Nov 13 '18 at 10:22
lee-pai-longlee-pai-long
84359
You can try converting the field list to a dict like this:
coll.find(, field: 1 for field in field_list)
answered Nov 13 '18 at 10:22
lee-pai-longlee-pai-long
84359
answered Nov 13 '18 at 10:22
lee-pai-longlee-pai-long
84359
answered Nov 13 '18 at 10:22
lee-pai-longlee-pai-long
84359
answered Nov 13 '18 at 10:22
lee-pai-longlee-pai-long
84359
84359
Thanks, it works perfectly!
– Dust009
Nov 13 '18 at 10:29
add a comment |
Thanks, it works perfectly!
– Dust009
Nov 13 '18 at 10:29
Thanks, it works perfectly!
– Dust009
Nov 13 '18 at 10:29
Thanks, it works perfectly!
– Dust009
Nov 13 '18 at 10:29
add a comment |
Thanks for contributing an answer to Stack Overflow!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53278292%2fpymongo-how-to-use-a-list-as-a-projection-in-find%23new-answer', 'question_page');
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
