diff --git a/MANIFEST.in b/MANIFEST.in
index 1c956cf9..106e29b1 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -3,6 +3,7 @@ include doc/wiki/using-mmgen/*
 
 include test/*.py
 include test/test_py_d/*.py
+include test/objtest_py_d/*.py
 include test/unit_tests_d/*.py
 include test/ref/*
 include test/ref/litecoin/*
diff --git a/test/objtest.py b/test/objtest.py
index a65f87d2..a863b3e2 100755
--- a/test/objtest.py
+++ b/test/objtest.py
@@ -101,284 +101,17 @@ def run_test(test,arg,input_data):
 		msg('==> {!r}'.format(ret))
 		die(2,red('{}'.format(e.args[0])))
 
-r32,r24,r16,r17,r18 = os.urandom(32),os.urandom(24),os.urandom(16),os.urandom(17),os.urandom(18)
-tw_pfx = g.proto.base_coin.lower()+':'
-utf8_text           = '[α-$ample UTF-8 text-ω]' * 10   # 230 chars, unicode types L,N,P,S,Z
-utf8_text_combining = '[α-$ámple UTF-8 téxt-ω]' * 10   # L,N,P,S,Z,M
-utf8_text_control   = '[α-$ample\nUTF-8\ntext-ω]' * 10 # L,N,P,S,Z,C
-
-from collections import OrderedDict
-
-tests = { 'BTC': {}, 'LTC': {} }
-
-tests['BTC']['mainnet'] = OrderedDict([
-	('AddrIdx', {
-		'bad':  ('s',1.1,12345678,-1),
-		'good': (('7',7),)
-	}),
-	('AddrIdxList', {
-		'bad':  ('x','5,9,1-2-3','8,-11','66,3-2'),
-		'good': (
-			('3,2,2',[2,3]),
-			('101,1,3,5,2-7,99',[1,2,3,4,5,6,7,99,101]),
-			({'idx_list':AddrIdxList('1-5')},[1,2,3,4,5])
-		)
-	}),
-	('SubSeedIdxRange', {
-		'bad':  (33,'x','-11','66,3','0','3-2','8000000','100000000',(1,2,3)),
-		'good': (
-			('3',(3,3)),
-			((3,5),(3,5)),
-			('1-2',(1,2)),
-			(str(g.subseeds),(g.subseeds,g.subseeds)),
-			(str(SubSeedIdxRange.max_idx),(SubSeedIdxRange.max_idx,SubSeedIdxRange.max_idx)),
-		)
-	}),
-	('BTCAmt', {
-		'bad':  ('-3.2','0.123456789',123,'123L','22000000',20999999.12345678),
-		'good': (('20999999.12345678',Decimal('20999999.12345678')),)
-	}),
-	('CoinAddr', {
-		'bad':  (1,'x','я'),
-		'good': ('1MjjELEy6EJwk8fSNfpS8b5teFRo4X5fZr','32GiSWo9zJQgkCmjAaLRrbPwXhKry2jHhj'),
-	}),
-	('SeedID', {
-		'bad':  (
-			{'sid':'я'},
-			{'sid':'F00F00'},
-			{'sid':'xF00F00x'},
-			{'sid':1},
-			{'sid':'F00BAA123'},
-			{'sid':'f00baa12'},
-			'я',r32,'abc'),
-		'good': (({'sid':'F00BAA12'},'F00BAA12'),(Seed(r16),Seed(r16).sid))
-	}),
-	('SubSeedIdx', {
-		'bad':  (33,'x','я','1x',200,'1ss','L','s','200LS','30ll','s100',str(SubSeedIdxRange.max_idx+1),'0'),
-		'good': (('1','1L'),('1s','1S'),'20S','30L',('300l','300L'),('200','200L'),str(SubSeedIdxRange.max_idx)+'S')
-	}),
-	('MMGenID', {
-		'bad':  ('x',1,'f00f00f','a:b','x:L:3','F00BAA12:0','F00BAA12:Z:99'),
-		'good': (('F00BAA12:99','F00BAA12:L:99'),'F00BAA12:L:99','F00BAA12:S:99')
-	}),
-	('TwMMGenID', {
-		'bad':  ('x','я','я:я',1,'f00f00f','a:b','x:L:3','F00BAA12:0','F00BAA12:Z:99',tw_pfx,tw_pfx+'я'),
-		'good': (('F00BAA12:99','F00BAA12:L:99'),'F00BAA12:L:99','F00BAA12:S:9999999',tw_pfx+'x')
-	}),
-	('TwLabel', {
-		'bad':  ('x x','x я','я:я',1,'f00f00f','a:b','x:L:3','F00BAA12:0 x',
-				'F00BAA12:Z:99',tw_pfx+' x',tw_pfx+'я x'),
-		'good': (
-			('F00BAA12:99 a comment','F00BAA12:L:99 a comment'),
-			'F00BAA12:L:99 comment (UTF-8) α',
-			'F00BAA12:S:9999999 comment',
-			tw_pfx+'x comment')
-	}),
-	('MMGenTxID', {
-		'bad':  (1,[],'\0','\1','я','g','gg','FF','f00','F00F0012'),
-		'good': ('DEADBE','F00BAA')
-	}),
-	('CoinTxID',{
-		'bad':  (1,[],'\0','\1','я','g','gg','FF','f00','F00F0012',r16.hex(),r32.hex()+'ee'),
-		'good': (r32.hex(),)
-	}),
-	('WifKey', {
-		'bad':  (1,[],'\0','\1','я','g','gg','FF','f00',r16.hex(),'2MspvWFjBbkv2wzQGqhxJUYPCk3Y2jMaxLN'),
-		'good': ('5KXEpVzjWreTcQoG5hX357s1969MUKNLuSfcszF6yu84kpsNZKb',
-				'KwWr9rDh8KK5TtDa3HLChEvQXNYcUXpwhRFUPc5uSNnMtqNKLFhk'),
-	}),
-	('PubKey', {
-		'bad':  ({'arg':1,'compressed':False},{'arg':'F00BAA12','compressed':False},),
-		'good': ({'arg':'deadbeef','compressed':True},) # TODO: add real pubkeys
-	}),
-	('PrivKey', {
-		'bad': (
-			{'wif':1},
-			{'wif':'1'},
-			{'wif':'cMsqcmDYZP1LdKgqRh9L4ZRU9br28yvdmTPwW2YQwVSN9aQiMAoR'},
-			{'s':r32,'wif':'5KXEpVzjWreTcQoG5hX357s1969MUKNLuSfcszF6yu84kpsNZKb'},
-			{'pubkey_type':'std'},
-			{'s':r32},
-			{'s':r32,'compressed':'yes'},
-			{'s':r32,'compressed':'yes','pubkey_type':'std'},
-			{'s':r32,'compressed':True,'pubkey_type':'nonstd'},
-			{'s':r32+b'x','compressed':True,'pubkey_type':'std'}
-		),
-		'good': (
-			{'wif':'5KXEpVzjWreTcQoG5hX357s1969MUKNLuSfcszF6yu84kpsNZKb',
-			'ret':'e0aef965b905a2fedf907151df8e0a6bac832aa697801c51f58bd2ecb4fd381c'},
-			{'wif':'KwWr9rDh8KK5TtDa3HLChEvQXNYcUXpwhRFUPc5uSNnMtqNKLFhk',
-			'ret':'08d0ed83b64b68d56fa064be48e2385060ed205be2b1e63cd56d218038c3a05f'},
-			{'s':r32,'compressed':False,'pubkey_type':'std','ret':r32.hex()},
-			{'s':r32,'compressed':True,'pubkey_type':'std','ret':r32.hex()}
-		)
-	}),
-	('AddrListID', { # a rather pointless test, but do it anyway
-		'bad':  (
-			{'sid':SeedID(sid='F00BAA12'),'mmtype':'Z','ret':'F00BAA12:Z'},
-		),
-		'good':  (
-			{'sid':SeedID(sid='F00BAA12'),'mmtype':MMGenAddrType('S'),'ret':'F00BAA12:S'},
-			{'sid':SeedID(sid='F00BAA12'),'mmtype':MMGenAddrType('L'),'ret':'F00BAA12:L'},
-		)
-	}),
-	('MMGenWalletLabel', {
-		'bad': (utf8_text[:49],utf8_text_combining[:48],utf8_text_control[:48]),
-		'good':  (utf8_text[:48],)
-	}),
-	('TwComment', {
-		'bad': (utf8_text[:41],utf8_text_combining[:40],utf8_text_control[:40]),
-		'good':  (utf8_text[:40],)
-	}),
-	('MMGenTXLabel',{
-		'bad': (utf8_text[:73],utf8_text_combining[:72],utf8_text_control[:72]),
-		'good':  (utf8_text[:72],)
-	}),
-	('MMGenPWIDString', { # forbidden = list(u' :/\\')
-		'bad': ('foo/','foo:','foo:\\'),
-		'good': ('qwerty@яяя',)
-	}),
-	('MMGenAddrType', {
-		'bad': ('U','z','xx',1,'dogecoin'),
-		'good':  (
-			{'s':'legacy','ret':'L'},
-			{'s':'L','ret':'L'},
-			{'s':'compressed','ret':'C'},
-			{'s':'C','ret':'C'},
-			{'s':'segwit','ret':'S'},
-			{'s':'S','ret':'S'},
-			{'s':'bech32','ret':'B'},
-			{'s':'B','ret':'B'}
-		)
-	}),
-	('MMGenPasswordType', {
-		'bad': ('U','z','я',1,'passw0rd'),
-		'good': (
-			{'s':'password','ret':'P'},
-			{'s':'P','ret':'P'},
-		)
-	}),
-	('ETHNonce', {
-		'bad': ('U','z','я',-1),
-		'good':  (('0',0),('1',1),('100',100),1,100)
-	}),
-])
-
-tests['BTC']['testnet'] = OrderedDict([
-	('CoinAddr', {
-		'bad':  (1,'x','я'),
-		'good': ('n2FgXPKwuFkCXF946EnoxWJDWF2VwQ6q8J','2MspvWFjBbkv2wzQGqhxJUYPCk3Y2jMaxLN'),
-	}),
-	('WifKey', {
-		'bad':  (1,[],'\0','\1','я','g','gg','FF','f00',r16.hex(),'2MspvWFjBbkv2wzQGqhxJUYPCk3Y2jMaxLN'),
-		'good': ('93HsQEpH75ibaUJYi3QwwiQxnkW4dUuYFPXZxcbcKds7XrqHkY6',
-				'cMsqcmDYZP1LdKgqRh9L4ZRU9br28yvdmTPwW2YQwVSN9aQiMAoR'),
-	}),
-	('PrivKey', {
-		'bad': (
-			{'wif':1},
-			{'wif':'1'},
-			{'wif':'5KXEpVzjWreTcQoG5hX357s1969MUKNLuSfcszF6yu84kpsNZKb'},
-			{'s':r32,'wif':'5KXEpVzjWreTcQoG5hX357s1969MUKNLuSfcszF6yu84kpsNZKb'},
-			{'pubkey_type':'std'},
-			{'s':r32},
-			{'s':r32,'compressed':'yes'},
-			{'s':r32,'compressed':'yes','pubkey_type':'std'},
-			{'s':r32,'compressed':True,'pubkey_type':'nonstd'},
-			{'s':r32+b'x','compressed':True,'pubkey_type':'std'}
-		),
-		'good': (
-			{'wif':'93HsQEpH75ibaUJYi3QwwiQxnkW4dUuYFPXZxcbcKds7XrqHkY6',
-			'ret':'e0aef965b905a2fedf907151df8e0a6bac832aa697801c51f58bd2ecb4fd381c'},
-			{'wif':'cMsqcmDYZP1LdKgqRh9L4ZRU9br28yvdmTPwW2YQwVSN9aQiMAoR',
-			'ret':'08d0ed83b64b68d56fa064be48e2385060ed205be2b1e63cd56d218038c3a05f'},
-			{'s':r32,'compressed':False,'pubkey_type':'std','ret':r32.hex()},
-			{'s':r32,'compressed':True,'pubkey_type':'std','ret':r32.hex()}
-		)
-	})
-])
-
-tests['LTC']['mainnet'] = OrderedDict([
-	('LTCAmt', {
-		'bad':  ('-3.2','0.123456789',123,'123L','88000000',80999999.12345678),
-		'good': (('80999999.12345678',Decimal('80999999.12345678')),)
-	}),
-	('CoinAddr', {
-		'bad':  (1,'x','я'),
-		'good': ('LXYx4j8PDGE8GEwDFnEQhcLyHFGsRxSJwt','MEnuCzUGHaQx9fK5WYvLwR1NK4SAo8HmSr'),
-	}),
-	('WifKey', {
-		'bad':  (1,[],'\0','\1','я','g','gg','FF','f00',r16.hex(),'2MspvWFjBbkv2wzQGqhxJUYPCk3Y2jMaxLN'),
-		'good': ('6udBAGS6B9RfGyvEQDkVDsWy3Kqv9eTULqtEfVkJtTJyHdLvojw',
-				'T7kCSp5E71jzV2zEJW4q5qU1SMB5CSz8D9VByxMBkamv1uM3Jjca'),
-	}),
-	('PrivKey', {
-		'bad': (
-			{'wif':1},
-			{'wif':'1'},
-			{'wif':'cMsqcmDYZP1LdKgqRh9L4ZRU9br28yvdmTPwW2YQwVSN9aQiMAoR'},
-			{'s':r32,'wif':'6ufJhtQQiRYA3w2QvDuXNXuLgPFp15i3HR1Wp8An2mx1JnhhJAh'},
-			{'pubkey_type':'std'},
-			{'s':r32},
-			{'s':r32,'compressed':'yes'},
-			{'s':r32,'compressed':'yes','pubkey_type':'std'},
-			{'s':r32,'compressed':True,'pubkey_type':'nonstd'},
-			{'s':r32+b'x','compressed':True,'pubkey_type':'std'}
-		),
-		'good': (
-			{'wif':'6ufJhtQQiRYA3w2QvDuXNXuLgPFp15i3HR1Wp8An2mx1JnhhJAh',
-			'ret':'470a974ffca9fca1299b706b09142077bea3acbab6d6480b87dbba79d5fd279b'},
-			{'wif':'T41Fm7J3mtZLKYPMCLVSFARz4QF8nvSDhLAfW97Ds56Zm9hRJgn8',
-			'ret':'1c6feab55a4c3b4ad1823d4ecacd1565c64228c01828cf44fb4db1e2d82c3d56'},
-			{'s':r32,'compressed':False,'pubkey_type':'std','ret':r32.hex()},
-			{'s':r32,'compressed':True,'pubkey_type':'std','ret':r32.hex()}
-		)
-	}),
-])
-
-tests['LTC']['testnet'] = OrderedDict([
-	('CoinAddr', {
-		'bad':  (1,'x','я'),
-		'good': ('n2D3joAy3yE5fqxUeCp38X6uPUcVn7EFw9','QN59YbnHsPQcbKWSq9PmTpjrhBnHGQqRmf')
-	}),
-	('WifKey', {
-		'bad':  (1,[],'\0','\1','я','g','gg','FF','f00',r16.hex(),'2MspvWFjBbkv2wzQGqhxJUYPCk3Y2jMaxLN'),
-		'good': ('936Fd4qs3Zy2ZiYHH7vZ3UpT23KtCAiGiG2xBTkjHo7jE9aWA2f',
-				'cQY3EumdaSNuttvDSUuPdiMYLyw8aVmYfFqxo9kdPuWbJBN4Ny66')
-	}),
-	('PrivKey', {
-		'bad': (
-			{'wif':1},
-			{'wif':'1'},
-			{'wif':'5KXEpVzjWreTcQoG5hX357s1969MUKNLuSfcszF6yu84kpsNZKb'},
-			{'s':r32,'wif':'5KXEpVzjWreTcQoG5hX357s1969MUKNLuSfcszF6yu84kpsNZKb'},
-			{'pubkey_type':'std'},
-			{'s':r32},
-			{'s':r32,'compressed':'yes'},
-			{'s':r32,'compressed':'yes','pubkey_type':'std'},
-			{'s':r32,'compressed':True,'pubkey_type':'nonstd'},
-			{'s':r32+b'x','compressed':True,'pubkey_type':'std'}
-		),
-		'good': (
-			{'wif':'92iqzh6NqiKawyB1ronw66YtEHrU4rxRJ5T4aHniZqvuSVZS21f',
-			'ret':'95b2aa7912550eacdd3844dcc14bee08ce7bc2434ad4858beb136021e945afeb'},
-			{'wif':'cSaJAXBAm9ooHpVJgoxqjDG3AcareFy29Cz8mhnNTRijjv2HLgta',
-			'ret':'94fa8b90c11fea8fb907c9376b919534b0a75b9a9621edf71a78753544b4101c'},
-			{'s':r32,'compressed':False,'pubkey_type':'std','ret':r32.hex()},
-			{'s':r32,'compressed':True,'pubkey_type':'std','ret':r32.hex()}
-		)
-	}),
-])
-
 def do_loop():
 	utests = cmd_args
 	network = ('mainnet','testnet')[bool(g.testnet)]
-	all_tests = tests[g.coin][network]
-	for test in all_tests:
+	gl = globals()
+	exec('from test.objtest_py_d.ot_{}_{} import tests'.format(g.coin.lower(),network),gl,gl)
+	gmsg('Running data objest tests for {} {}'.format(g.coin,network))
+	for test in tests:
 		if utests and test not in utests: continue
 		msg((blue,nocolor)[bool(opt.super_silent)]('Testing {}'.format(test)))
 		for k in ('bad','good'):
-			for arg in all_tests[test][k]:
+			for arg in tests[test][k]:
 				run_test(test,arg,input_data=k)
 
 do_loop()
diff --git a/test/objtest_py_d/__init__.py b/test/objtest_py_d/__init__.py
new file mode 100755
index 00000000..e69de29b
diff --git a/test/objtest_py_d/ot_btc_mainnet.py b/test/objtest_py_d/ot_btc_mainnet.py
new file mode 100755
index 00000000..3026baff
--- /dev/null
+++ b/test/objtest_py_d/ot_btc_mainnet.py
@@ -0,0 +1,182 @@
+#!/usr/bin/env python3
+#
+# mmgen = Multi-Mode GENerator, command-line Bitcoin cold storage solution
+# Copyright (C)2013-2019 The MMGen Project <mmgen@tuta.io>
+
+"""
+test.objtest_py_d.ot_btc_mainnet: BTC mainnet test vectors for MMGen data objects
+"""
+
+from collections import OrderedDict
+
+from mmgen.obj import *
+from mmgen.seed import *
+from .ot_common import *
+
+tests = OrderedDict([
+	('AddrIdx', {
+		'bad':  ('s',1.1,12345678,-1),
+		'good': (('7',7),)
+	}),
+	('AddrIdxList', {
+		'bad':  ('x','5,9,1-2-3','8,-11','66,3-2'),
+		'good': (
+			('3,2,2',[2,3]),
+			('101,1,3,5,2-7,99',[1,2,3,4,5,6,7,99,101]),
+			({'idx_list':AddrIdxList('1-5')},[1,2,3,4,5])
+		)
+	}),
+	('SubSeedIdxRange', {
+		'bad':  (33,'x','-11','66,3','0','3-2','8000000','100000000',(1,2,3)),
+		'good': (
+			('3',(3,3)),
+			((3,5),(3,5)),
+			('1-2',(1,2)),
+			(str(g.subseeds),(g.subseeds,g.subseeds)),
+			(str(SubSeedIdxRange.max_idx),(SubSeedIdxRange.max_idx,SubSeedIdxRange.max_idx)),
+		)
+	}),
+	('BTCAmt', {
+		'bad':  ('-3.2','0.123456789',123,'123L','22000000',20999999.12345678,
+					{'num':'1','from_decimal':True},
+					{'num':1,'from_decimal':True},
+				),
+		'good': (('20999999.12345678',Decimal('20999999.12345678')),
+				{'num':Decimal('1.23456789623456789'),'from_decimal':True,'ret':Decimal('1.23456790')}, # rounding
+				{'num':Decimal('1.234'),'from_decimal':True,'ret':Decimal('1.234')},
+				{'num':Decimal('0.0'),'from_decimal':True,'ret':Decimal('0')},
+				# emulate network fee estimation:
+				#                  BTC/kB         tx_fee_adj       tx size
+				{   'num':Decimal('0.00053249') * Decimal('0.9') * 109 / 1024 , # ≈53 sat/byte
+					'from_decimal':True,
+					'ret':Decimal('0.00005101') },
+				{   'num':Decimal('0.00003249') * Decimal('1.1') * 109 / 1024 , # ≈3 sat/byte
+					'from_decimal':True,
+					'ret':Decimal('0.00000380') },
+				{   'num':Decimal('0.00011249') * Decimal('1.0') * 221 / 1024 , # ≈11 sat/byte
+					'from_decimal':True,
+					'ret':Decimal('0.00002428') },
+				{'num':1234,'from_unit':'satoshi','ret':Decimal('0.00001234')},
+		)
+	}),
+	('CoinAddr', {
+		'bad':  (1,'x','я'),
+		'good': ('1MjjELEy6EJwk8fSNfpS8b5teFRo4X5fZr','32GiSWo9zJQgkCmjAaLRrbPwXhKry2jHhj'),
+	}),
+	('SeedID', {
+		'bad':  (
+			{'sid':'я'},
+			{'sid':'F00F00'},
+			{'sid':'xF00F00x'},
+			{'sid':1},
+			{'sid':'F00BAA123'},
+			{'sid':'f00baa12'},
+			'я',r32,'abc'),
+		'good': (({'sid':'F00BAA12'},'F00BAA12'),(Seed(r16),Seed(r16).sid))
+	}),
+	('SubSeedIdx', {
+		'bad':  (33,'x','я','1x',200,'1ss','L','s','200LS','30ll','s100',str(SubSeedIdxRange.max_idx+1),'0'),
+		'good': (('1','1L'),('1s','1S'),'20S','30L',('300l','300L'),('200','200L'),str(SubSeedIdxRange.max_idx)+'S')
+	}),
+	('MMGenID', {
+		'bad':  ('x',1,'f00f00f','a:b','x:L:3','F00BAA12:0','F00BAA12:Z:99'),
+		'good': (('F00BAA12:99','F00BAA12:L:99'),'F00BAA12:L:99','F00BAA12:S:99')
+	}),
+	('TwMMGenID', {
+		'bad':  ('x','я','я:я',1,'f00f00f','a:b','x:L:3','F00BAA12:0','F00BAA12:Z:99',tw_pfx,tw_pfx+'я'),
+		'good': (('F00BAA12:99','F00BAA12:L:99'),'F00BAA12:L:99','F00BAA12:S:9999999',tw_pfx+'x')
+	}),
+	('TwLabel', {
+		'bad':  ('x x','x я','я:я',1,'f00f00f','a:b','x:L:3','F00BAA12:0 x',
+				'F00BAA12:Z:99',tw_pfx+' x',tw_pfx+'я x'),
+		'good': (
+			('F00BAA12:99 a comment','F00BAA12:L:99 a comment'),
+			'F00BAA12:L:99 comment (UTF-8) α',
+			'F00BAA12:S:9999999 comment',
+			tw_pfx+'x comment')
+	}),
+	('MMGenTxID', {
+		'bad':  (1,[],'\0','\1','я','g','gg','FF','f00','F00F0012'),
+		'good': ('DEADBE','F00BAA')
+	}),
+	('CoinTxID',{
+		'bad':  (1,[],'\0','\1','я','g','gg','FF','f00','F00F0012',r16.hex(),r32.hex()+'ee'),
+		'good': (r32.hex(),)
+	}),
+	('WifKey', {
+		'bad':  (1,[],'\0','\1','я','g','gg','FF','f00',r16.hex(),'2MspvWFjBbkv2wzQGqhxJUYPCk3Y2jMaxLN'),
+		'good': ('5KXEpVzjWreTcQoG5hX357s1969MUKNLuSfcszF6yu84kpsNZKb',
+				'KwWr9rDh8KK5TtDa3HLChEvQXNYcUXpwhRFUPc5uSNnMtqNKLFhk'),
+	}),
+	('PubKey', {
+		'bad':  ({'arg':1,'compressed':False},{'arg':'F00BAA12','compressed':False},),
+		'good': ({'arg':'deadbeef','compressed':True},) # TODO: add real pubkeys
+	}),
+	('PrivKey', {
+		'bad': (
+			{'wif':1},
+			{'wif':'1'},
+			{'wif':'cMsqcmDYZP1LdKgqRh9L4ZRU9br28yvdmTPwW2YQwVSN9aQiMAoR'},
+			{'s':r32,'wif':'5KXEpVzjWreTcQoG5hX357s1969MUKNLuSfcszF6yu84kpsNZKb'},
+			{'pubkey_type':'std'},
+			{'s':r32},
+			{'s':r32,'compressed':'yes'},
+			{'s':r32,'compressed':'yes','pubkey_type':'std'},
+			{'s':r32,'compressed':True,'pubkey_type':'nonstd'},
+			{'s':r32+b'x','compressed':True,'pubkey_type':'std'}
+		),
+		'good': (
+			{'wif':'5KXEpVzjWreTcQoG5hX357s1969MUKNLuSfcszF6yu84kpsNZKb',
+			'ret':'e0aef965b905a2fedf907151df8e0a6bac832aa697801c51f58bd2ecb4fd381c'},
+			{'wif':'KwWr9rDh8KK5TtDa3HLChEvQXNYcUXpwhRFUPc5uSNnMtqNKLFhk',
+			'ret':'08d0ed83b64b68d56fa064be48e2385060ed205be2b1e63cd56d218038c3a05f'},
+			{'s':r32,'compressed':False,'pubkey_type':'std','ret':r32.hex()},
+			{'s':r32,'compressed':True,'pubkey_type':'std','ret':r32.hex()}
+		)
+	}),
+	('AddrListID', { # a rather pointless test, but do it anyway
+		'bad':  (
+			{'sid':SeedID(sid='F00BAA12'),'mmtype':'Z','ret':'F00BAA12:Z'},
+		),
+		'good':  (
+			{'sid':SeedID(sid='F00BAA12'),'mmtype':MMGenAddrType('S'),'ret':'F00BAA12:S'},
+			{'sid':SeedID(sid='F00BAA12'),'mmtype':MMGenAddrType('L'),'ret':'F00BAA12:L'},
+		)
+	}),
+	('MMGenWalletLabel', {
+		'bad': (utf8_text[:49],utf8_text_combining[:48],utf8_text_control[:48]),
+		'good':  (utf8_text[:48],)
+	}),
+	('TwComment', {
+		'bad': (utf8_text[:41],utf8_text_combining[:40],utf8_text_control[:40]),
+		'good':  (utf8_text[:40],)
+	}),
+	('MMGenTXLabel',{
+		'bad': (utf8_text[:73],utf8_text_combining[:72],utf8_text_control[:72]),
+		'good':  (utf8_text[:72],)
+	}),
+	('MMGenPWIDString', { # forbidden = list(u' :/\\')
+		'bad': ('foo/','foo:','foo:\\'),
+		'good': ('qwerty@яяя',)
+	}),
+	('MMGenAddrType', {
+		'bad': ('U','z','xx',1,'dogecoin'),
+		'good':  (
+			{'s':'legacy','ret':'L'},
+			{'s':'L','ret':'L'},
+			{'s':'compressed','ret':'C'},
+			{'s':'C','ret':'C'},
+			{'s':'segwit','ret':'S'},
+			{'s':'S','ret':'S'},
+			{'s':'bech32','ret':'B'},
+			{'s':'B','ret':'B'}
+		)
+	}),
+	('MMGenPasswordType', {
+		'bad': ('U','z','я',1,'passw0rd'),
+		'good': (
+			{'s':'password','ret':'P'},
+			{'s':'P','ret':'P'},
+		)
+	}),
+])
diff --git a/test/objtest_py_d/ot_btc_testnet.py b/test/objtest_py_d/ot_btc_testnet.py
new file mode 100755
index 00000000..bd610531
--- /dev/null
+++ b/test/objtest_py_d/ot_btc_testnet.py
@@ -0,0 +1,47 @@
+#!/usr/bin/env python3
+#
+# mmgen = Multi-Mode GENerator, command-line Bitcoin cold storage solution
+# Copyright (C)2013-2019 The MMGen Project <mmgen@tuta.io>
+
+"""
+test.objtest_py_d.ot_btc_testnet: BTC testnet test vectors for MMGen data objects
+"""
+
+from collections import OrderedDict
+
+from mmgen.obj import *
+from .ot_common import *
+
+tests = OrderedDict([
+	('CoinAddr', {
+		'bad':  (1,'x','я'),
+		'good': ('n2FgXPKwuFkCXF946EnoxWJDWF2VwQ6q8J','2MspvWFjBbkv2wzQGqhxJUYPCk3Y2jMaxLN'),
+	}),
+	('WifKey', {
+		'bad':  (1,[],'\0','\1','я','g','gg','FF','f00',r16.hex(),'2MspvWFjBbkv2wzQGqhxJUYPCk3Y2jMaxLN'),
+		'good': ('93HsQEpH75ibaUJYi3QwwiQxnkW4dUuYFPXZxcbcKds7XrqHkY6',
+				'cMsqcmDYZP1LdKgqRh9L4ZRU9br28yvdmTPwW2YQwVSN9aQiMAoR'),
+	}),
+	('PrivKey', {
+		'bad': (
+			{'wif':1},
+			{'wif':'1'},
+			{'wif':'5KXEpVzjWreTcQoG5hX357s1969MUKNLuSfcszF6yu84kpsNZKb'},
+			{'s':r32,'wif':'5KXEpVzjWreTcQoG5hX357s1969MUKNLuSfcszF6yu84kpsNZKb'},
+			{'pubkey_type':'std'},
+			{'s':r32},
+			{'s':r32,'compressed':'yes'},
+			{'s':r32,'compressed':'yes','pubkey_type':'std'},
+			{'s':r32,'compressed':True,'pubkey_type':'nonstd'},
+			{'s':r32+b'x','compressed':True,'pubkey_type':'std'}
+		),
+		'good': (
+			{'wif':'93HsQEpH75ibaUJYi3QwwiQxnkW4dUuYFPXZxcbcKds7XrqHkY6',
+			'ret':'e0aef965b905a2fedf907151df8e0a6bac832aa697801c51f58bd2ecb4fd381c'},
+			{'wif':'cMsqcmDYZP1LdKgqRh9L4ZRU9br28yvdmTPwW2YQwVSN9aQiMAoR',
+			'ret':'08d0ed83b64b68d56fa064be48e2385060ed205be2b1e63cd56d218038c3a05f'},
+			{'s':r32,'compressed':False,'pubkey_type':'std','ret':r32.hex()},
+			{'s':r32,'compressed':True,'pubkey_type':'std','ret':r32.hex()}
+		)
+	})
+])
diff --git a/test/objtest_py_d/ot_common.py b/test/objtest_py_d/ot_common.py
new file mode 100755
index 00000000..fc92ab02
--- /dev/null
+++ b/test/objtest_py_d/ot_common.py
@@ -0,0 +1,17 @@
+#!/usr/bin/env python3
+#
+# mmgen = Multi-Mode GENerator, command-line Bitcoin cold storage solution
+# Copyright (C)2013-2019 The MMGen Project <mmgen@tuta.io>
+
+"""
+test.objtest_py_d.ot_common: shared data for MMGen data objects tests
+"""
+
+import os
+from mmgen.globalvars import g
+
+r32,r24,r16,r17,r18 = os.urandom(32),os.urandom(24),os.urandom(16),os.urandom(17),os.urandom(18)
+tw_pfx = g.proto.base_coin.lower()+':'
+utf8_text           = '[α-$ample UTF-8 text-ω]' * 10   # 230 chars, unicode types L,N,P,S,Z
+utf8_text_combining = '[α-$ámple UTF-8 téxt-ω]' * 10   # L,N,P,S,Z,M
+utf8_text_control   = '[α-$ample\nUTF-8\ntext-ω]' * 10 # L,N,P,S,Z,C
diff --git a/test/objtest_py_d/ot_eth_mainnet.py b/test/objtest_py_d/ot_eth_mainnet.py
new file mode 100755
index 00000000..afbe689f
--- /dev/null
+++ b/test/objtest_py_d/ot_eth_mainnet.py
@@ -0,0 +1,35 @@
+#!/usr/bin/env python3
+#
+# mmgen = Multi-Mode GENerator, command-line Bitcoin cold storage solution
+# Copyright (C)2013-2019 The MMGen Project <mmgen@tuta.io>
+
+"""
+test.objtest_py_d.ot_eth_mainnet: ETH mainnet test vectors for MMGen data objects
+"""
+
+from collections import OrderedDict
+
+from mmgen.obj import *
+from .ot_common import *
+
+tests = OrderedDict([
+	('ETHAmt', {
+		'bad':  ('-3.2','0.1234567891234567891',123,'123L',
+					{'num':'1','from_decimal':True},
+					{'num':1,'from_decimal':True},
+				),
+		'good': (('123.123456789123456789',Decimal('123.123456789123456789')),
+				{   'num':Decimal('1.12345678912345678892345'), # rounding
+					'from_decimal':True,
+					'ret':Decimal('1.123456789123456789')},
+				{'num':Decimal('1.234'),'from_decimal':True,'ret':Decimal('1.234')},
+				{'num':Decimal('0.0'),'from_decimal':True,'ret':Decimal('0')},
+				{'num':1234,'from_unit':'wei','ret':Decimal('0.000000000000001234')},
+				{'num':1234,'from_unit':'Mwei','ret':Decimal('0.000000001234')},
+		)
+	}),
+	('ETHNonce', {
+		'bad': ('U','z','я',-1),
+		'good':  (('0',0),('1',1),('100',100),1,100)
+	}),
+])
diff --git a/test/objtest_py_d/ot_ltc_mainnet.py b/test/objtest_py_d/ot_ltc_mainnet.py
new file mode 100755
index 00000000..ee2baa2f
--- /dev/null
+++ b/test/objtest_py_d/ot_ltc_mainnet.py
@@ -0,0 +1,51 @@
+#!/usr/bin/env python3
+#
+# mmgen = Multi-Mode GENerator, command-line Bitcoin cold storage solution
+# Copyright (C)2013-2019 The MMGen Project <mmgen@tuta.io>
+
+"""
+test.objtest_py_d.ot_ltc_mainnet: LTC mainnet test vectors for MMGen data objects
+"""
+
+from collections import OrderedDict
+
+from mmgen.obj import *
+from .ot_common import *
+
+tests = OrderedDict([
+	('LTCAmt', {
+		'bad':  ('-3.2','0.123456789',123,'123L','88000000',80999999.12345678),
+		'good': (('80999999.12345678',Decimal('80999999.12345678')),)
+	}),
+	('CoinAddr', {
+		'bad':  (1,'x','я'),
+		'good': ('LXYx4j8PDGE8GEwDFnEQhcLyHFGsRxSJwt','MEnuCzUGHaQx9fK5WYvLwR1NK4SAo8HmSr'),
+	}),
+	('WifKey', {
+		'bad':  (1,[],'\0','\1','я','g','gg','FF','f00',r16.hex(),'2MspvWFjBbkv2wzQGqhxJUYPCk3Y2jMaxLN'),
+		'good': ('6udBAGS6B9RfGyvEQDkVDsWy3Kqv9eTULqtEfVkJtTJyHdLvojw',
+				'T7kCSp5E71jzV2zEJW4q5qU1SMB5CSz8D9VByxMBkamv1uM3Jjca'),
+	}),
+	('PrivKey', {
+		'bad': (
+			{'wif':1},
+			{'wif':'1'},
+			{'wif':'cMsqcmDYZP1LdKgqRh9L4ZRU9br28yvdmTPwW2YQwVSN9aQiMAoR'},
+			{'s':r32,'wif':'6ufJhtQQiRYA3w2QvDuXNXuLgPFp15i3HR1Wp8An2mx1JnhhJAh'},
+			{'pubkey_type':'std'},
+			{'s':r32},
+			{'s':r32,'compressed':'yes'},
+			{'s':r32,'compressed':'yes','pubkey_type':'std'},
+			{'s':r32,'compressed':True,'pubkey_type':'nonstd'},
+			{'s':r32+b'x','compressed':True,'pubkey_type':'std'}
+		),
+		'good': (
+			{'wif':'6ufJhtQQiRYA3w2QvDuXNXuLgPFp15i3HR1Wp8An2mx1JnhhJAh',
+			'ret':'470a974ffca9fca1299b706b09142077bea3acbab6d6480b87dbba79d5fd279b'},
+			{'wif':'T41Fm7J3mtZLKYPMCLVSFARz4QF8nvSDhLAfW97Ds56Zm9hRJgn8',
+			'ret':'1c6feab55a4c3b4ad1823d4ecacd1565c64228c01828cf44fb4db1e2d82c3d56'},
+			{'s':r32,'compressed':False,'pubkey_type':'std','ret':r32.hex()},
+			{'s':r32,'compressed':True,'pubkey_type':'std','ret':r32.hex()}
+		)
+	}),
+])
diff --git a/test/objtest_py_d/ot_ltc_testnet.py b/test/objtest_py_d/ot_ltc_testnet.py
new file mode 100755
index 00000000..14fa8311
--- /dev/null
+++ b/test/objtest_py_d/ot_ltc_testnet.py
@@ -0,0 +1,47 @@
+#!/usr/bin/env python3
+#
+# mmgen = Multi-Mode GENerator, command-line Bitcoin cold storage solution
+# Copyright (C)2013-2019 The MMGen Project <mmgen@tuta.io>
+
+"""
+test.objtest_py_d.ot_ltc_testnet: LTC testnet test vectors for MMGen data objects
+"""
+
+from collections import OrderedDict
+
+from mmgen.obj import *
+from .ot_common import *
+
+tests = OrderedDict([
+	('CoinAddr', {
+		'bad':  (1,'x','я'),
+		'good': ('n2D3joAy3yE5fqxUeCp38X6uPUcVn7EFw9','QN59YbnHsPQcbKWSq9PmTpjrhBnHGQqRmf')
+	}),
+	('WifKey', {
+		'bad':  (1,[],'\0','\1','я','g','gg','FF','f00',r16.hex(),'2MspvWFjBbkv2wzQGqhxJUYPCk3Y2jMaxLN'),
+		'good': ('936Fd4qs3Zy2ZiYHH7vZ3UpT23KtCAiGiG2xBTkjHo7jE9aWA2f',
+				'cQY3EumdaSNuttvDSUuPdiMYLyw8aVmYfFqxo9kdPuWbJBN4Ny66')
+	}),
+	('PrivKey', {
+		'bad': (
+			{'wif':1},
+			{'wif':'1'},
+			{'wif':'5KXEpVzjWreTcQoG5hX357s1969MUKNLuSfcszF6yu84kpsNZKb'},
+			{'s':r32,'wif':'5KXEpVzjWreTcQoG5hX357s1969MUKNLuSfcszF6yu84kpsNZKb'},
+			{'pubkey_type':'std'},
+			{'s':r32},
+			{'s':r32,'compressed':'yes'},
+			{'s':r32,'compressed':'yes','pubkey_type':'std'},
+			{'s':r32,'compressed':True,'pubkey_type':'nonstd'},
+			{'s':r32+b'x','compressed':True,'pubkey_type':'std'}
+		),
+		'good': (
+			{'wif':'92iqzh6NqiKawyB1ronw66YtEHrU4rxRJ5T4aHniZqvuSVZS21f',
+			'ret':'95b2aa7912550eacdd3844dcc14bee08ce7bc2434ad4858beb136021e945afeb'},
+			{'wif':'cSaJAXBAm9ooHpVJgoxqjDG3AcareFy29Cz8mhnNTRijjv2HLgta',
+			'ret':'94fa8b90c11fea8fb907c9376b919534b0a75b9a9621edf71a78753544b4101c'},
+			{'s':r32,'compressed':False,'pubkey_type':'std','ret':r32.hex()},
+			{'s':r32,'compressed':True,'pubkey_type':'std','ret':r32.hex()}
+		)
+	}),
+])
diff --git a/test/test-release.sh b/test/test-release.sh
index 240ac8a7..0eda290f 100755
--- a/test/test-release.sh
+++ b/test/test-release.sh
@@ -193,6 +193,7 @@ t_obj="
 	$objtest_py --coin=btc --testnet=1
 	$objtest_py --coin=ltc
 	$objtest_py --coin=ltc --testnet=1
+	$objtest_py --coin=eth
 "
 f_obj='Data object test complete'