import urllib.parse

url = 'http://hostname.domain/mypage.asp?fields=id&query=%22((release%3D{id%3D1004});(sprint%3D{id%3D1040});(team%3D{id%3D1004});(severity%3D{id%3D%27list_node.severity.urgent%27});!phase%3D{id+IN+%27phase.defect.closed%27,%27phase.defect.duplicate%27,%27phase.defect.rejected%27})%22'

parsedURL = urllib.parse.urlparse(url)
parsedQueryTouple = urllib.parse.parse_qsl(parsedURL.query, keep_blank_values=True, errors='surrogateescape')

for item in parsedQueryTouple:
    print(str(item))