大约有 47,000 项符合查询结果（耗时：0.0539秒） [XML]
Rename specific column(s) in pandas
...
30
A much faster implementation would be to use list-comprehension if you need to rename a single c...
Cost of exception handlers in Python
...e just tried the following:
import timeit
statements=["""\
try:
b = 10/a
except ZeroDivisionError:
pass""",
"""\
if a:
b = 10/a""",
"b = 10/a"]
for a in (1,0):
for s in statements:
t = timeit.Timer(stmt=s, setup='a={}'.format(a))
print("a = {}\n{}".format(a,s))
...
What is this operator in MySQL?
...e the regular = operator, two values are compared and the result is either 0 (not equal) or 1 (equal); in other words: 'a' <=> 'b' yields 0 and 'a' <=> 'a' yields 1.
Unlike the regular = operator, values of NULL don't have a special meaning and so it never yields NULL as a possible outco...
How to join absolute and relative urls?
...> import urlparse
>>> urlparse.urljoin(url1, url2)
'http://127.0.0.1/test1/test4/test6.xml'
With Python 3 (where urlparse is renamed to urllib.parse) you could use it as follow:
>>> import urllib.parse
>>> urllib.parse.urljoin(url1, url2)
'http://127.0.0.1/test1/test...
PDOException SQLSTATE[HY000] [2002] No such file or directory
...
answered Dec 22 '13 at 19:08
ukautzukautz
1,99311 gold badge1111 silver badges77 bronze badges
...
Code Golf: Collatz Conjecture
Inspired by http://xkcd.com/710/ here is a code golf for it.
70 Answers
70
...
Return a value if no rows are found in Microsoft tSQL
...hat doesn't exist then I will get nothing returned. I'd prefer that false (0) is returned in that scenario. Looking for the simplest method to account for no records.
...
How do you add swap to an EC2 instance?
...
10 Answers
10
Active
...
Common MySQL fields and their appropriate data types
...
answered Dec 10 '08 at 0:57
da5idda5id
8,83288 gold badges3636 silver badges5050 bronze badges
...
How to convert an integer to a string in any base?
...tring.digits + string.ascii_letters
def int2base(x, base):
if x < 0:
sign = -1
elif x == 0:
return digs[0]
else:
sign = 1
x *= sign
digits = []
while x:
digits.append(digs[int(x % base)])
x = int(x / base)
if sign < 0:
...