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Practice

Tips for Using format() Function - indexError

When using the format() function, if the number of curly braces {} in the string does not match the number of arguments passed to the format() function, an indexError exception will occur.

An indexError happens when there are more curly braces in the string than there are parameters passed to the function, resulting in a failure to find a value to map to a brace.


indexError Example
greeting = "Hello, {0}! Today is {1}. {2}"

try:
    formatted_greeting = greeting.format("CodeFriend", "Tuesday")
    print(formatted_greeting)

except IndexError as e:
    print(f"Error occurred: {e}")

Resolving indexError​

To prevent indexError, ensure the number of curly braces in the string matches the number of parameters passed to the format() function.

Resolved indexError
# Remove {2} to resolve the indexError
greeting = "Hello, {0}! Today is {1}."
formatted_greeting = greeting.format("Chris", "Tuesday")

print(formatted_greeting)  # "Hello, Chris! Today is Tuesday."

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