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Replace a value in a data frame based on a conditional (`if`) statement
... <- as.character(junk$nm)
junk$nm[junk$nm == "B"] <- "b"
EDIT: And if indeed you need to maintain nm as factors, add this in the end:
junk$nm <- as.factor(junk$nm)
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Calculate difference in keys contained in two Python dictionaries
...e I have two Python dictionaries - dictA and dictB . I need to find out if there are any keys which are present in dictB but not in dictA . What is the fastest way to go about it?
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How to read a line from the console in C?
...0), * linep = line;
size_t lenmax = 100, len = lenmax;
int c;
if(line == NULL)
return NULL;
for(;;) {
c = fgetc(stdin);
if(c == EOF)
break;
if(--len == 0) {
len = lenmax;
char * linen = realloc(linep, lenmax *= 2)...
How to loop through a directory recursively to delete files with certain extensions
...or loop, instead of using xargs. I often find xargs cumbersome, especially if I need to do something more complicated in each iteration.
for f in $(find /tmp -name '*.pdf' -or -name '*.doc'); do rm $f; done
As a number of people have commented, this will fail if there are spaces in filenames. You...
LEFT JOIN vs. LEFT OUTER JOIN in SQL Server
What is the difference between LEFT JOIN and LEFT OUTER JOIN ?
12 Answers
12
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Case insensitive searching in Oracle
... versions older than 10gR2 it can't really be done and the usual approach, if you don't need accent-insensitive search, is to just UPPER() both the column and the search expression.
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htmlentities() vs. htmlspecialchars()
What are the differences between htmlspecialchars() and htmlentities() . When should I use one or the other?
12 Answers
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Cannot set some HTTP headers when using System.Net.WebRequest
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If you need the short and technical answer go right to the last section of the answer.
If you want to know better, read it all, and i hope you'll enjoy...
I countered this problem too today, and what i discovered today is...
When to use dynamic vs. static libraries
... dynamic ( .dll , .so ) and static ( .lib , .a ) libraries. What is the difference between them and when is it appropriate to use which?
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CSS hide scroll bar if not needed
I am trying to figure out how I can hide the overflow-y:scroll; if not needed. What I mean is that I am building a website and I have a main area which posts will be displayed and I want to hide the scroll bar if content does not exceed the current width.
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