สรุป / ประเมินวิธีการที่มีอยู่:
Candidate | type | delnan | mat | shrewmouse | ant6n
-------------------------------------------------------------------------
0 | <type 'int'> | 1 | 1 | 1 | 1
0.0 | <type 'float'> | 1 | 1 | 1 | 1
0j | <type 'complex'> | 1 | 1 | 1 | 0
Decimal('0') | <class 'decimal.Decimal'> | 1 | 0 | 1 | 1
True | <type 'bool'> | 1 | 1 | 1 | 1
False | <type 'bool'> | 1 | 1 | 1 | 1
'' | <type 'str'> | 0 | 0 | 0 | 0
None | <type 'NoneType'> | 0 | 0 | 0 | 0
'0' | <type 'str'> | 0 | 0 | 0 | 1
'1' | <type 'str'> | 0 | 0 | 0 | 1
[] | <type 'list'> | 0 | 0 | 0 | 0
[1] | <type 'list'> | 0 | 0 | 0 | 0
[1, 2] | <type 'list'> | 0 | 0 | 0 | 0
(1,) | <type 'tuple'> | 0 | 0 | 0 | 0
(1, 2) | <type 'tuple'> | 0 | 0 | 0 | 0
(ฉันมาที่นี่ด้วยคำถามนี้ )
รหัส
#!/usr/bin/env python
"""Check if a variable is a number."""
import decimal
def delnan_is_number(candidate):
import numbers
return isinstance(candidate, numbers.Number)
def mat_is_number(candidate):
return isinstance(candidate, (int, long, float, complex))
def shrewmouse_is_number(candidate):
try:
return 0 == candidate * 0
except:
return False
def ant6n_is_number(candidate):
try:
float(candidate)
return True
except:
return False
# Test
candidates = (0, 0.0, 0j, decimal.Decimal(0),
True, False, '', None, '0', '1', [], [1], [1, 2], (1, ), (1, 2))
methods = [delnan_is_number, mat_is_number, shrewmouse_is_number, ant6n_is_number]
print("Candidate | type | delnan | mat | shrewmouse | ant6n")
print("-------------------------------------------------------------------------")
for candidate in candidates:
results = [m(candidate) for m in methods]
print("{:<12} | {:<25} | {:>6} | {:>3} | {:>10} | {:>5}"
.format(repr(candidate), type(candidate), *results))