micropython/tests/basics/string-format.py

# Change the following to True to get a much more comprehensive set of tests
# to run, albeit, which take considerably longer.

full_tests = False

def test(fmt, *args):
    print('{:8s}'.format(fmt) + '>' +  fmt.format(*args) + '<')

test("{}-{}", 1, [4, 5])
test("{0}-{1}", 1, [4, 5])
test("{1}-{0}", 1, [4, 5])
test("{:x}", 1)
test("{!r}", 2)
test("{:x}", 0x10)
test("{!r}", "foo")
test("{!s}", "foo")
test("{0!r:>10s} {0!s:>10s}", "foo")

test("{:4b}", 10)
test("{:4c}", 48)
test("{:4d}", 123)
test("{:4n}", 123)
test("{:4o}", 123)
test("{:4x}", 123)
test("{:4X}", 123)

test("{:4,d}", 12345678)

test("{:#4b}", 10)
test("{:#4o}", 123)
test("{:#4x}", 123)
test("{:#4X}", 123)

test("{:#4d}", 0)
test("{:#4b}", 0)
test("{:#4o}", 0)
test("{:#4x}", 0)
test("{:#4X}", 0)

test("{:<6s}", "ab")
test("{:>6s}", "ab")
test("{:^6s}", "ab")

test("{: <6d}", 123)
test("{: <6d}", -123)
test("{:0<6d}", 123)
test("{:0<6d}", -123)
test("{:@<6d}", 123)
test("{:@<6d}", -123)

test("{:@< 6d}", 123)
test("{:@< 6d}", -123)
test("{:@<+6d}", 123)
test("{:@<+6d}", -123)
test("{:@<-6d}", 123)
test("{:@<-6d}", -123)

test("{:@>6d}",  -123)
test("{:@<6d}",  -123)
test("{:@=6d}",  -123)
test("{:06d}",  -123)

test("{:10.4e}", 123.456)
test("{:10.4e}", -123.456)
test("{:10.4f}", 123.456)
test("{:10.4f}", -123.456)
test("{:10.4g}", 123.456)
test("{:10.4g}", -123.456)
test("{:e}", 100)
test("{:f}", 200)
test("{:g}", 300)

test("{:10.4E}", 123.456)
test("{:10.4E}", -123.456)
test("{:10.4F}", 123.456)
test("{:10.4F}", -123.456)
test("{:10.4G}", 123.456)
test("{:10.4G}", -123.456)

# The following fails right now
#test("{:10.1}", 0.0)

def test_fmt(conv, fill, alignment, sign, prefix, width, precision, type, arg):
    fmt = '{'
    if conv:
        fmt += '!'
        fmt += conv
    fmt += ':'
    if alignment:
        fmt += fill
        fmt += alignment
    fmt += sign
    fmt += prefix
    fmt += width
    if precision:
        fmt += '.'
        fmt += precision
    fmt += type
    fmt += '}'
    test(fmt,  arg)
    if fill == '0' and alignment == '=':
        fmt = '{:'
        fmt += sign
        fmt += prefix
        fmt += width
        if precision:
            fmt += '.'
            fmt += precision
        fmt += type
        fmt += '}'
        test(fmt, arg)

int_nums = (-1234, -123, -12, -1, 0, 1, 12, 123, 1234, True, False)
int_nums2 = (-12, -1, 0, 1, 12, True, False)

if full_tests:
    for type in ('', 'b', 'd', 'o', 'x', 'X'):
        for width in ('', '1', '3', '5', '7'):
            for alignment in ('', '<', '>', '=', '^'):
                for fill in ('', ' ', '0', '@'):
                    for sign in ('', '+', '-', ' '):
                        for prefix in ('', '#'):
                            for num in int_nums:
                                test_fmt('', fill, alignment, sign, prefix, width, '', type, num)

if full_tests:
    for width in ('', '1', '2'):
        for alignment in ('', '<', '>', '^'):
            for fill in ('', ' ', '0', '@'):
                test_fmt('', fill, alignment, '', '', width, '', 'c', 48)

if full_tests:
    for conv in ('', 'r', 's'):
        for width in ('', '1', '4', '10'):
            for alignment in ('', '<', '>', '^'):
                for fill in ('', ' ', '0', '@'):
                    for str in ('', 'a', 'bcd', 'This is a test with a longer string'):
                        test_fmt(conv, fill, alignment, '', '', width, '', 's', str)

eg_nums = (0.0, -0.0, 0.1, 1.234, 12.3459, 1.23456789, 123456789.0, -0.0,
    -0.1, -1.234, -12.3459, 1e4, 1e-4, 1e5, 1e-5, 1e6, 1e-6, 1e10,
    1e37, -1e37, 1e-37, -1e-37,
    1.23456e8, 1.23456e7, 1.23456e6, 1.23456e5, 1.23456e4, 1.23456e3, 1.23456e2, 1.23456e1, 1.23456e0,
    1.23456e-1, 1.23456e-2, 1.23456e-3, 1.23456e-4, 1.23456e-5, 1.23456e-6, 1.23456e-7, 1.23456e-8,
    -1.23456e8, -1.23456e7, -1.23456e6, -1.23456e5, -1.23456e4, -1.23456e3, -1.23456e2, -1.23456e1, -1.23456e0,
    -1.23456e-1, -1.23456e-2, -1.23456e-3, -1.23456e-4, -1.23456e-5, -1.23456e-6, -1.23456e-7, -1.23456e-8)

if full_tests:
    for type in ('e', 'E', 'g', 'G', 'n'):
        for width in ('', '4', '6', '8', '10'):
            for alignment in ('', '<', '>', '=', '^'):
                for fill in ('', '@', '0', ' '):
                    for sign in ('', '+', '-', ' '):
                        for prec in ('', '1', '3', '6'):
                            for num in eg_nums:
                                test_fmt('', fill, alignment, sign, '', width, prec, type, num)

# Note: We use 1.23459 rather than 1.2345 because '{:3f}'.format(1.2345)
#       rounds differently than print("%.3f", 1.2345);

f_nums = (0.0, -0.0, 0.0001, 0.001, 0.01, 0.1, 1.0, 10.0,
     0.0012,  0.0123,  0.1234,  1.23459,  12.3456,
    -0.0001, -0.001,  -0.01,   -0.1,      -1.0, -10.0,
    -0.0012, -0.0123, -0.1234, -1.23459, -12.3456)

if full_tests:
    for type in ('f', 'F'):
        for width in ('', '4', '6', '8', '10'):
            for alignment in ('', '<', '>', '=', '^'):
                for fill in ('', ' ', '0', '@'):
                    for sign in ('', '+', '-', ' '):
                        # An empty precision defaults to 6, but when uPy is
                        # configured to use a float, we can only use a
                        # precision of 6 with numbers less than 10 and still
                        # get results that compare to CPython (which uses
                        # long doubles).
                        for prec in ('1', '2', '3'):
                            for num in f_nums:
                                test_fmt('', fill, alignment, sign, '', width, prec, type, num)
                        for num in int_nums2:
                            test_fmt('', fill, alignment, sign, '', width, '', type, num)

pct_nums1 = (0.1, 0.58, 0.99, -0.1, -0.58, -0.99)
pct_nums2 = (True, False, 1, 0, -1)

if full_tests:
    type = '%'
    for width in ('', '4', '6', '8', '10'):
        for alignment in ('', '<', '>', '=', '^'):
            for fill in ('', ' ', '0', '@'):
                for sign in ('', '+', '-', ' '):
                    # An empty precision defaults to 6, but when uPy is
                    # configured to use a float, we can only use a
                    # precision of 6 with numbers less than 10 and still
                    # get results that compare to CPython (which uses
                    # long doubles).
                    for prec in ('1', '2', '3'):
                        for num in pct_nums1:
                            test_fmt('', fill, alignment, sign, '', width, prec, type, num)
                    for num in pct_nums2:
                        test_fmt('', fill, alignment, sign, '', width, '', type, num)

# We don't currently test a type of '' with floats (see the detailed comment
# in  objstr.c)

# TODO Add tests for erroneous format strings.