Value Error unsupported format character '"' when using % string formatting

Question

I'm trying to use string formatting to convert incoming CSV to XML. I'm getting the following error:

ValueError: unsupported format character '"' (0x22) at index 36

I understand that I'm using an " somewhere I shouldn't but can't find where that is. The " inside the template should all be encapsulated inside the """ ... """ and I can't see any elsewhere in the script.

Could anyone suggest where I've gone wrong?

import csv
import sys


def csvDict(csvRow):
    dict = {'Name': csvRow[0], 'p1t': csvRow[1], 'p1l': csvRow[2], 'p2t': csvRow[3], 'p2l': csvRow[4],
            'outputWidth': csvRow[5], 'sourceTop': csvRow[6], 'sourceLeft': csvRow[7], 'sourceWidth': csvRow[8],
            'sourceHeight': csvRow[9]}
    return dict


# Get CSV File from the argument
csvFile = csv.reader(open(sys.argv[1], 'rt'))

# Convert CSV Into list for Processing
csvList = list(csvFile)

# Setup XML Variables Dictionary
outputVars = csvDict(csvList[0])

# Confirm Dictionary contains the right data
print outputVars


# XML Format Template
mapTemplate = """<map type="map2dpanel" name="%(Name)" width="%(outputWidth)" >
        <point id="1" top="%(p1t)" left="%(p1l)" /><point id="2" top="%(p2t)" left="%(p2l)" />
        <source image="current source" top="%(sourceTop)" left="%(sourceLeft)" width="%(sourceWidth)" height="%(sourceHeight)" />
    </map>
"""

print mapTemplate % outputVars

Answer 1

You forgot to specify the type of placeholder. Python expects %(name)s or %(name)d or any of the other supported types .

Instead, Python finds " to be the next character, which is not a valid format character:

name="%(Name)"
#     -------^

Since you are reading the values from a CSV file, they'll all be strings; add s characters to your template placeholders:

mapTemplate = """\
    <map type="map2dpanel" name="%(Name)s" width="%(outputWidth)s" >
        <point id="1" top="%(p1t)s" left="%(p1l)s" /><point id="2" top="%(p2t)s" left="%(p2l)s" />
        <source image="current source" top="%(sourceTop)s" left="%(sourceLeft)s" width="%(sourceWidth)s" height="%(sourceHeight)s" />
    </map>
"""