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How to add pandas data to an existing csv file?
... I was able to accomplish it by re-read the 'my_csv.csv', then concat the new df, and then save it. If you know some easier method, please DO let me know. I appreciate!
– datanew
Nov 9 '18 at 21:56
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Replacing all non-alphanumeric characters with empty strings
...ter, since only the first occurrence of "^" is negating the meaning of the selection. [^\\p{IsAlphabetic}\\p{IsDigit}] works well.
– Bogdan Klichuk
Jan 19 '18 at 17:22
1
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Remove portion of a string after a certain character
...
+1 It's the only one that works if the control characters are NOT present (unlike the others that return an empty string if the control characters are not present in the source string)
– Tom Auger
Apr 28 '15 at 2:26
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Why is “int i = 2147483647 + 1;” OK, but “byte b = 127 + 1;” is not compilable?
... if the expression is a constant expression (§15.28) of type byte, short, char or int :
A narrowing primitive conversion may be used if the type of the variable is byte, short, or char, and the value of the constant expression is representable in the type of the variable.
Without this clause, ...
How can I hash a password in Java?
...te[16];
random.nextBytes(salt);
KeySpec spec = new PBEKeySpec("password".toCharArray(), salt, 65536, 128);
SecretKeyFactory f = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
byte[] hash = f.generateSecret(spec).getEncoded();
Base64.Encoder enc = Base64.getEncoder();
System.out.printf("salt: %s...
Java HotSpot(TM) 64-Bit Server VM warning: ignoring option MaxPermSize
...maven script /$MAVEN-HOME/bin/mvn, found the following line
MAVEN_OPTS="$(concat_lines "$MAVEN_PROJECTBASEDIR/.mvn/jvm.config") $MAVEN_OPTS"
Where $MAVEN_PROJECTBASEDIR by default is your home directory.
So two places you can take a look, first is file $MAVEN_PROJECTBASEDIR/.mvn/jvm.config if it ...
How does this print “hello world”?
...01100100100111110111111110111101100011000010101000
The program decodes a character for every 5-bits group, from right to left
00100|01100|10010|01111|10111|11111|01111|01100|01100|00101|01000
d | l | r | o | w | | o | l | l | e | h
5-bit codification
For 5 bits, it is...
How to replace all occurrences of a character in string?
What is the effective way to replace all occurrences of a character with another character in std::string ?
15 Answers
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How can I create directory tree in C++/Linux?
...#include "sysstat.h"
typedef struct stat Stat;
static int do_mkdir(const char *path, mode_t mode)
{
Stat st;
int status = 0;
if (stat(path, &st) != 0)
{
/* Directory does not exist. EEXIST for race condition */
if (mkdir(path, mode) != 0 ...
Passing base64 encoded strings in URL
...ed to url-encode it, since base64 strings can contain the "+", "=" and "/" characters which could alter the meaning of your data - look like a sub-folder.
Valid base64 characters are below.
ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=
...