import sys
sys.path.append(r'/path_to_pycades_so')
import pycades
from lxml import etree

store = pycades.Store()
store.Open(pycades.CADESCOM_CONTAINER_STORE, pycades.CAPICOM_MY_STORE, pycades.CAPICOM_STORE_OPEN_MAXIMUM_ALLOWED)
certs = store.Certificates
assert(certs.Count != 0), "Certificates with private key not found"

signer = pycades.Signer()
signer.Certificate = certs.Item(1)
signer.CheckCertificate = True

doc = etree.parse('test.txt', etree.XMLParser(encoding='ISO-8859-1', ns_clean=True, recover=True))

content_to_sign = etree.tostring(doc, pretty_print=False, encoding='unicode')

signedXML = pycades.SignedXML()
signedXML.Content = content_to_sign
#signedXML.SignatureType = pycades.CADESCOM_XML_SIGNATURE_TYPE_ENVELOPED | pycades.CADESCOM_XADES_BES
signedXML.SignatureType = pycades.CADESCOM_XML_SIGNATURE_TYPE_TEMPLATE | pycades.CADESCOM_XADES_BES
message = signedXML.Sign(signer)

print(message)

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/"
                  xmlns:ds="http://www.w3.org/2000/09/xmldsig#"
                  xmlns:v2="http://history.smev.ru/v2/"
                  xmlns:wsse="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd"
                  xmlns:wsu="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd">
	<soapenv:Header>
				<wsse:BinarySecurityToken EncodingType="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-soap-message-security-1.0#Base64Binary"
			                          ValueType="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-x509-token-profile-1.0#X509v3"
			                          wsu:Id="CertId-0DA773FF46AF4146A6B28772356CBFC7">
			</wsse:BinarySecurityToken>
			<ds:Signature>
				<ds:SignedInfo>
					<ds:CanonicalizationMethod Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#"/>
					<ds:SignatureMethod Algorithm="http://www.w3.org/2001/04/xmldsig-more#gostr34102001-gostr3411"/>
					<ds:Reference URI="#BodyId-F6AC1DDCAC4D4FBF9078EEB332F502C4">
						<ds:Transforms>
							<ds:Transform Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#"/>
						</ds:Transforms>
						<ds:DigestMethod Algorithm="http://www.w3.org/2001/04/xmldsig-more#gostr3411"/>
						<ds:DigestValue/>
					</ds:Reference>
				</ds:SignedInfo>
				<ds:SignatureValue>
				</ds:SignatureValue>
				<ds:KeyInfo>
					<wsse:SecurityTokenReference>
						<wsse:Reference URI="#CertId-0DA773FF46AF4146A6B28772356CBFC7"
						                ValueType="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-x509-token-profile-1.0#X509v3"/>
					</wsse:SecurityTokenReference>
				</ds:KeyInfo>
			</ds:Signature>
	</soapenv:Header>
	<soapenv:Body wsu:Id="BodyId-F6AC1DDCAC4D4FBF9078EEB332F502C4">
		<v2:newActionRequest>
			<v2:actionCode/>
			<v2:addAppId/>
			<v2:addAppIdCode/>
			<v2:addSocId/>
			<v2:addSocIdCode/>
			<v2:applicantId/>
			<v2:date/>
			<v2:empFio/>
			<v2:empId/>
			<v2:empJob/>
			<v2:finished/>
			<v2:fromIS/>
			<v2:innerId/>
			<v2:linkedAction/>
			<v2:name/>
			<v2:orgName/>
			<v2:ownerOrg/>
			<v2:rguId/>
			<v2:actionSoap>
				<v2:path/>
				<v2:length/>
				<v2:body/>
				<v2:name/>
			</v2:actionSoap>
			<v2:socId/>
			<v2:status/>
			<v2:statusDate/>
			<v2:toIS/>
			<v2:type/>
			<v2:uniqId/>
		</v2:newActionRequest>
	</soapenv:Body>
</soapenv:Envelope>