大约有 43,100 项符合查询结果（耗时：0.0457秒） [XML]
R - Concatenate two dataframes?
...ine adds column b to data frame b.
Results
> a <- data.frame(a=c(0,1,2), b=c(3,4,5), c=c(6,7,8))
> a
a b c
1 0 3 6
2 1 4 7
3 2 5 8
> b <- data.frame(a=c(9,10,11), c=c(12,13,14))
> b
a c
1 9 12
2 10 13
3 11 14
> b$b <- NA
> b
a c b
1 9 12 NA
2 10 13 NA
3 11 1...
How to get the process ID to kill a nohup process?
...
13 Answers
13
Active
...
Using python's eval() vs. ast.literal_eval()?
...
193
datamap = eval(raw_input('Provide some data here: ')) means that you actually evaluate the cod...
Size of character ('a') in C/C++
... the size of character in C and C++ ? As far as I know the size of char is 1 byte in both C and C++.
4 Answers
...
How to identify server IP address in PHP
...
15 Answers
15
Active
...
How to convert a string or integer to binary in Ruby?
...a string representing the number in the base specified:
9.to_s(2) #=> "1001"
while the reverse is obtained with String#to_i(base):
"1001".to_i(2) #=> 9
share
|
improve this answer
...
Turn Pandas Multi-Index into column
...
197
The reset_index() is a pandas DataFrame method that will transfer index values into the DataFr...
How do I execute a command and get the output of the command within C++ using POSIX?
...
11 Answers
11
Active
...
Android : Check whether the phone is dual SIM
...
184
Update 23 March'15 :
Official multiple SIM API is available now from Android 5.1 onwards ...
Difference between two dates in Python
...nd take the days member.
from datetime import datetime
def days_between(d1, d2):
d1 = datetime.strptime(d1, "%Y-%m-%d")
d2 = datetime.strptime(d2, "%Y-%m-%d")
return abs((d2 - d1).days)
share
|
...