CODEWITHSUNDEEP
pythonpython-3.x
user1187968
user1187968

Reputation: 7986

Python: Triple Double Quote String format

I'm getting the following error, how should I fix it?

KeyError: 'a' Process finished with exit code 1

s = """
a b c {a}
""".format({'a':'123'})

print s

Upvotes: 4

Views: 2353

Answers (3)

wim
wim

Reputation: 362488

Named formatting variables must be passed by name:

>>> s = """
... a b c {a}
... """.format(a=123)
>>> print(s)

a b c 123

If you're providing a dict of data, you can "unpack" the names:

>>> d = {'a': 123}
>>> s = """
... a b c {a}
... """.format(**d)
>>> print(s)

a b c 123

Upvotes: 3

Asad Moosvi
Asad Moosvi

Reputation: 490

You are using the format method for strings incorrectly. format requires that you pass in keyword arguments when you want to substitute names inside a string.

The correct form to use the method in your case would be the following:

s = """
a b c {a}
""".format(a='123')

print s

However if you do want to pass in a dictionary, then you can unpack it into keyword arguments by prepending ** before the dictionary itself. This will unpack the dictionary into the the keyword argument of a='123' like the code above.

Please read more about Python strings and the string format method here.

Upvotes: 1

MSeifert
MSeifert

Reputation: 152587

You need to pass in the arguments by name .format(a=123) or use format_map which expects a dictionary:

s = """
a b c {a}
""".format_map({'a':'123'})

Upvotes: 6

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