assert 'testing' == 'test' + 'ing'
assert 'testing' != 'test' + 'ing2'
assert 'testing' < 'test' + 'ing2'
assert 'testing5' > 'test' + 'ing1'

# test + *=
assert 'abc' + 'def' == 'abcdef'
assert 'abc' * 3 == 'abcabcabc'

a = ''
b = 'test'
c ='test'
assert len(a) == 0
assert len(b) == 4
assert b == c

# upper and lower does not work for utf-8
assert ''.lower() == '' and ''.upper() == ''
assert 'already+lower '.lower() == 'already+lower '
assert 'ALREADY+UPPER '.upper() == 'ALREADY+UPPER '
assert 'tEST+InG'.lower() == 'test+ing'
assert 'tEST+InG'.upper() == 'TEST+ING'

s = "football"
q = "abcd"
r = "zoo"
t = "this is string example....wow!!!"
assert s[0] == 'f'
assert s[1:4] == 'oot'
assert s[:-1] == 'footbal'
assert s[:10] == 'football'
assert s[-3] == 'a'
assert t[-5:] == 'ow!!!'
assert t[3:-3] == 's is string example....wow'
assert s > q;assert s < r
assert s.replace("foo","ball") == "balltball"
assert s.startswith('f') == True;assert s.endswith('o') == False
assert t.startswith('this') == True;


assert t.split('w') == ['this is string example....', 'o', '!!!']
assert "a,b,c".split(',') == ['a', 'b', 'c']
assert 'a,'.split(',') == ['a', '']
assert 'foo!!bar!!baz'.split('!!') == ['foo', 'bar', 'baz']
assert ' 4 3 '.split() == ['4', '3']
assert '  4 3  '.split(' ') == ['', '', '4', '3', '', '']

assert '111'.count('1') == 3
assert '111'.count('11') == 1
assert '1111'.count('11') == 2
assert '11'.count('') == 3
assert ''.count('1') == 0
assert ''.count('') == 1

t = "*****this is **string** example....wow!!!*****"
s = "123abcrunoob321"
assert t.strip( '*' ) == "this is **string** example....wow!!!"
assert s.strip( '12' ) == "3abcrunoob3"

assert t.strip( '*' ) == "this is **string** example....wow!!!"
assert s.strip( '12' ) == "3abcrunoob3"

s = ' asd\n  asd \n'
assert s.strip() == 'asd\n  asd'

s1 = "-"
s2 = ""
seq = ["r","u","n","o","o","b"]
assert s1.join( seq ) == "r-u-n-o-o-b"
assert s2.join( seq ) == "runoob"

assert 'x'.zfill(5) == '0000x'
assert '568'.zfill(1) == '568'

def test(*seq):
    return s1.join(seq)
assert test("r", "u", "n", "o", "o", "b") == "r-u-n-o-o-b"

def f():
    for i in range(5):
        yield str(i)
assert '|'.join(f()) == '0|1|2|3|4'

num = 6
assert str(num) == '6'

# test Lo group names

测试 = "test"
assert 测试 == "test"

assert "Hello, {}!".format("World") == "Hello, World!"
assert "{} {} {}".format("I", "love", "Python") == "I love Python"
assert "{0} {1} {2}".format("I", "love", "Python") == "I love Python"
assert "{2} {1} {0}".format("I", "love", "Python") == "Python love I"
assert "{0}{1}{0}".format("abra", "cad") == "abracadabra"

# 3rd slice
a = "Hello, World!"
assert a[::-1] == "!dlroW ,olleH"
assert a[::2] == "Hlo ol!"
assert a[2:5:2] == "lo"
assert a[5:2:-1] == ",ol"
assert a[5:2:-2] == ",l"

b = list(a)
assert b == ['H', 'e', 'l', 'l', 'o', ',', ' ', 'W', 'o', 'r', 'l', 'd', '!']
assert b[::-1] == ['!', 'd', 'l', 'r', 'o', 'W', ' ', ',', 'o', 'l', 'l', 'e', 'H']
assert b[::2] == ['H', 'l', 'o', ' ', 'o', 'l', '!']
assert b[2:5:2] == ['l', 'o']
assert b[5:2:-1] == [',', 'o', 'l']
assert b[5:2:-2] == [',', 'l']

a = '123'
assert a.rjust(5) == '  123'
assert a.rjust(5, '0') == '00123'
assert a.ljust(5) == '123  '
assert a.ljust(5, '0') == '12300'

assert '\x30\x31\x32' == '012'