all Python 3configparserexception

configparser.InterpolationSyntaxError

exceptions

Raised when a value contains % (or $ with extended interpolation) that is not followed by a valid reference.

Syntax

except configparser.InterpolationSyntaxError as e: ...

The usual case is '50%', a URL with %20 or a password with a percent sign in the INI file. The file reads without errors and get() fails. Fix it by doubling %% in the file, with get(..., raw=True) or with ConfigParser(interpolation=None). Writing the same string with set() raises ValueError, not this exception.

Examples

import configparser
cfg = configparser.ConfigParser()
cfg.read_string("[web]\nurl = /a%20b\n")
try:
    cfg.get("web", "url")
except configparser.InterpolationSyntaxError as e:
    print(e)  # → '%' must be followed by '%' or '(', found: '%20b'
print(cfg.get("web", "url", raw=True))  # → /a%20b

import configparser
cfg = configparser.ConfigParser()
cfg.add_section("web")
try:
    cfg.set("web", "rate", "5%")
except ValueError as e:
    print(type(e).__name__)  # → ValueError

See also

Common errors

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