CODEWITHSUNDEEP
pythonpython-3.x
zhuguowei
zhuguowei

Reputation: 8487

escaping str format brackets

I'd like to print something like the string below using Python:

{"_id":ObjectId("5a43ae09e2bae06ddd400dfc")}

At first I thought it would be easy, but it is not.

Here is my first attempt: 

'{"_id":ObjectId("{}")}'.format('5a43ae09e2bae06ddd400dfc')

But I got the following error

Traceback (most recent call last): File "", line 1, in KeyError: '"_id"'

Then I tried:

'\{"_id":ObjectId("{}")\}'.format('5a43ae09e2bae06ddd400dfc')

And I got this error

Traceback (most recent call last): File "", line 1, in KeyError: '"_id"'

I managed to make it work with the following code:

'{"_id":ObjectId("%s")}' %('5a43ae09e2bae06ddd400dfc')
'{"_id":ObjectId("5a43ae09e2bae06ddd400dfc")}'

What's wrong with str format?

Upvotes: 2

Views: 186

Answers (1)

Isma
Isma

Reputation: 15209

You need to escape your brackets so Python can tell the difference between a format parameter and a character that needs to be printed out, to do that you can just duplicate the brackets as follows:

print('{{"_id":ObjectId("{}")}}'.format('5a43ae09e2bae06ddd400dfc'))

Here is more info: https://docs.python.org/3/library/string.html#formatstrings

Upvotes: 3

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