Python: Triple Double Quote String format

Question

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

Answer 1

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'})

Answer 2

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