Python string literal throwing errors with place holders

Question

I have a list as : token_found = ["abcdxyz", "1234567"]

I have a multiline string as below:

user_creds_string = """
UserA_A:
    - name: 'Abcd'
      value: '{0}'
UserB_B:
    - name: 'Abcd'
      value: '{1}'
headers:
  - name: 'Abcd'
    value: 'Kota %(xyz)'
    inputs:
      apop: {'type':'hex-64', 'required': True} 
  - name: 'X-Broke'
    value: '%(BId) %(blahId)'
    inputs:
      UkID: {'type':'hex-16', 'required': True} 
      blahId: {'type':'hex-64', 'required': True} 
apis:
    """.format(token_found[0],token_found[1])

Now when I run the above code I expect that the place holders {0} and {1} to be replaced with the values abcdxyz and 1234567 respectively, unless I am doing something wrong and which I do not understand.

Contrary to my assumption, I am getting the below error: KeyError: "'type'"

score 2 · Accepted Answer · answered Nov 03 '17 at 09:05

curly brackets {, } should be doubled to print them literally:

token_found = ["abcdxyz", "1234567"]
user_creds_string = """
UserA_A:
    - name: 'Abcd'
      value: '{0}'
UserB_B:
    - name: 'Abcd'
      value: '{1}'
headers:
  - name: 'Abcd'
    value: 'Kota %(xyz)'
    inputs:
      apop: {{'type':'hex-64', 'required': True}}
  - name: 'X-Broke'
    value: '%(BId) %(blahId)'
    inputs:
      UkID: {{'type':'hex-16', 'required': True}}
      blahId: {{'type':'hex-64', 'required': True}}
apis:
    """.format(token_found[0],token_found[1])

print(user_creds_string)

The output:

UserA_A:
    - name: 'Abcd'
      value: 'abcdxyz'
UserB_B:
    - name: 'Abcd'
      value: '1234567'
headers:
  - name: 'Abcd'
    value: 'Kota %(xyz)'
    inputs:
      apop: {'type':'hex-64', 'required': True}
  - name: 'X-Broke'
    value: '%(BId) %(blahId)'
    inputs:
      UkID: {'type':'hex-16', 'required': True}
      blahId: {'type':'hex-64', 'required': True}
apis:

thanks ! I did not know this. :) – qre0ct Nov 03 '17 at 09:20 — qre0ct, Nov 03 '17 at 09:20
@qre0ct, you're welcome – RomanPerekhrest Nov 03 '17 at 09:26 — RomanPerekhrest, Nov 03 '17 at 09:26

score 1 · Answer 2 · answered Nov 03 '17 at 09:03

1

You need to escape the {. format sees the pattern {'type' and tries to do a lookup of 'type' in the kwargs of format.

Escape as I recall is to double the brace, {{.

answered Nov 03 '17 at 09:03

wmorrell

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Yeah, got that from Roman's answer above. Thanks anyway :) – qre0ct Nov 03 '17 at 17:18

Python string literal throwing errors with place holders

2 Answers2