mirror of
https://github.com/licsber/micropython.git
synced 2024-09-20 00:50:24 +08:00
6f4d424f46
Rework the conversion of floats to decimal strings so it aligns precisely with the conversion of strings to floats in parsenum.c. This is to avoid rendering 1eX as 9.99999eX-1 etc. This is achieved by removing the power- of-10 tables and using pow() to compute the exponent directly, and that's done efficiently by first estimating the power-of-10 exponent from the power-of-2 exponent in the floating-point representation. Code size is reduced by roughly 100 to 200 bytes by this commit. Signed-off-by: Dan Ellis <dan.ellis@gmail.com>
53 lines
1.5 KiB
Python
53 lines
1.5 KiB
Python
print("%s" % 1.0)
|
|
print("%r" % 1.0)
|
|
|
|
print("%d" % 1.0)
|
|
print("%i" % 1.0)
|
|
print("%u" % 1.0)
|
|
|
|
# these 3 have different behaviour in Python 3.x versions
|
|
# uPy raises a TypeError, following Python 3.5 (earlier versions don't)
|
|
# print("%x" % 18.0)
|
|
# print("%o" % 18.0)
|
|
# print("%X" % 18.0)
|
|
|
|
print("%e" % 1.23456)
|
|
print("%E" % 1.23456)
|
|
print("%f" % 1.23456)
|
|
print("%F" % 1.23456)
|
|
print("%g" % 1.23456)
|
|
print("%G" % 1.23456)
|
|
|
|
print("%06e" % float("inf"))
|
|
print("%06e" % float("-inf"))
|
|
print("%06e" % float("nan"))
|
|
|
|
print("%02.3d" % 123) # prec > width
|
|
print("%+f %+f" % (1.23, -1.23)) # float sign
|
|
print("% f % f" % (1.23, -1.23)) # float space sign
|
|
print("%0f" % -1.23) # negative number with 0 padding
|
|
|
|
# numbers with large negative exponents
|
|
print("%f" % 1e-10)
|
|
print("%f" % 1e-20)
|
|
print("%f" % 1e-50)
|
|
print("%f" % 1e-100)
|
|
print("%f" % 1e-300)
|
|
|
|
# large decimal precision should be truncated and not overflow buffer
|
|
# the output depends on the FP calculation so only first 2 digits are printed
|
|
# (the 'g' with small e are printed using 'f' style, so need to be checked)
|
|
print(("%.40f" % 1e-300)[:2])
|
|
print(("%.40g" % 1e-1)[:2])
|
|
print(("%.40g" % 1e-2)[:2])
|
|
print(("%.40g" % 1e-3)[:2])
|
|
# Under Appveyor Release builds, 1e-4 was being formatted as 9.99999...e-5
|
|
# instead of 0.0001. (Interestingly, it formatted correctly for the Debug
|
|
# build). Avoid the edge case.
|
|
print(("%.40g" % 1.1e-4)[:2])
|
|
|
|
print("%.0g" % 1) # 0 precision 'g'
|
|
|
|
print("%.1e" % 9.99) # round up with positive exponent
|
|
print("%.1e" % 0.999) # round up with negative exponent
|