Not intended as a guide for newbies, more like a "cheat sheet" for the somewhat experienced IRC user, especially one who wields some power over a channel.
/join #channel
- Joins the specified channel.
/part #channel
- Leaves the specified channel.
def splitDataFrameList(df,target_column,separator): | |
''' df = dataframe to split, | |
target_column = the column containing the values to split | |
separator = the symbol used to perform the split | |
returns: a dataframe with each entry for the target column separated, with each element moved into a new row. | |
The values in the other columns are duplicated across the newly divided rows. | |
''' | |
def splitListToRows(row,row_accumulator,target_column,separator): | |
split_row = row[target_column].split(separator) |
#!/usr/bin/env bash | |
# first argument of the script is Xapian version (e.g. 1.2.19) | |
VERSION=$1 | |
# prepare | |
mkdir $VIRTUAL_ENV/packages && cd $VIRTUAL_ENV/packages | |
CORE=xapian-core-$VERSION | |
BINDINGS=xapian-bindings-$VERSION |
Magic words:
psql -U postgres
Some interesting flags (to see all, use -h
or --help
depending on your psql version):
-E
: will describe the underlaying queries of the \
commands (cool for learning!)-l
: psql will list all databases and then exit (useful if the user you connect with doesn't has a default database, like at AWS RDS)Single-line comments are started with //
. Multi-line comments are started with /*
and ended with */
.
C# uses braces ({
and }
) instead of indentation to organize code into blocks.
If a block is a single line, the braces can be omitted. For example,
L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns
Compress 1K bytes with Zippy ............. 3,000 ns = 3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns = 20 µs
SSD random read ........................ 150,000 ns = 150 µs
Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs