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How to import CSV file data into a PostgreSQL table?
...lution paraphrased here:
Create your table:
CREATE TABLE zip_codes
(ZIP char(5), LATITUDE double precision, LONGITUDE double precision,
CITY varchar, STATE char(2), COUNTY varchar, ZIP_CLASS varchar);
Copy data from your CSV file to the table:
COPY zip_codes FROM '/path/to/csv/ZIP_CODES.txt' ...
Get all non-unique values (i.e.: duplicate/more than one occurrence) in an array
... i, arr) => arr.indexOf(v) !== i && acc.indexOf(v) === -1 ? acc.concat(v) : acc, [])
– ZephDavies
Nov 29 '18 at 14:56
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In VIM, how do I break one really long line into multiple lines?
Say I have a super long line in the VIM editor (say around 300+ characters). How would I break that up into multiple lines so that the word boundaries roughly break at 80 characters?
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What is the difference between const int*, const int * const, and int const *?
...ften this is seen with C-style strings where you have a pointer to a const char. You may change which string you point to but you can't change the content of these strings. This is important when the string itself is in the data segment of a program and shouldn't be changed.
bar is a constant or fi...
Limits of Nat type in Shapeless
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Here is an example of a Concat type class that allows to concatenate two type-level strings via a macro. A type class for summing type-level integers would probably look very similar.
– Frank S. Thomas
Apr 16 '...
Why is using the JavaScript eval function a bad idea?
...name to: badHackerGuy'); doMaliciousThings(); and if you take my username, concat it into some script and eval it in other people's browsers then I can run any javascript I want on their machines (e.g. force them to +1 my posts, post their data to my server, etc.)
– Prestaul
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Combine two columns of text in pandas dataframe
...
if both columns are strings, you can concatenate them directly:
df["period"] = df["Year"] + df["quarter"]
If one (or both) of the columns are not string typed, you should convert it (them) first,
df["period"] = df["Year"].astype(str) + df["quarter"]
Beware...
Bitwise operation and usage
...(where n is the bit number, and 0 is the least significant bit):
unsigned char a |= (1 << n);
Clear a bit:
unsigned char b &= ~(1 << n);
Toggle a bit:
unsigned char c ^= (1 << n);
Test a bit:
unsigned char e = d & (1 << n);
Take the case of your list for exampl...
How to prevent gcc optimizing some statements in C?
...ore by using the volatile type qualifier.
// Assuming pageptr is unsigned char * already...
unsigned char *pageptr = ...;
((unsigned char volatile *)pageptr)[0] = pageptr[0];
The volatile type qualifier instructs the compiler to be strict about memory stores and loads. One purpose of volatile is...
Hash function that produces short hashes?
...ay of encryption that can take a string of any length and produce a sub-10-character hash? I want to produce reasonably unique ID's but based on message contents, rather than randomly.
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