Formatting string mixes implicitly and explicitly numbered fields¶
ID: py/str-format/mixed-fields Kind: problem Security severity: Severity: error Precision: high Tags: - quality - reliability - correctness Query suites: - python-code-quality.qls - python-security-and-quality.qls
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A formatting expression, that is an expression of the form the_format.format(args) or format(the_format, args), can use explicitly numbered fields, like {1}, or implicitly numbered fields, such as {}, but it cannot use both. Doing so will raise a ValueError.
Recommendation¶
Use either explicitly numbered fields or implicitly numbered fields, but be consistent.
Example¶
In the following example the formatting uses both implicit, {}, and explicit, {1}, numbering for fields, which is illegal.
def illegal_format(): "{} {1}".format("spam", "eggs")
References¶
Python Library Reference: String Formatting.