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How do I retrieve the number of columns in a Pandas data frame?
...the number of columns.
And for those who want the number of rows:
len(df.index)
For a tuple containing the number of both rows and columns:
df.shape
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Rotating and spacing axis labels in ggplot2
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Change the last line to
q + theme(axis.text.x = element_text(angle = 90, vjust = 0.5, hjust=1))
By default, the axes are aligned at the center of the text, even when rotated. When you rotate +/- 90 degrees, you usually want it to be aligned at th...
sqlalchemy: how to join several tables by one query?
... @PetrusTheron Like I said, query will yield 3-tuples. You can index elements, or just unpack: for (user, doc, perm) in query: print "Document: %s" % doc
– letitbee
Oct 15 '16 at 16:39
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How to remove old Docker containers
This question is related to Should I be concerned about excess, non-running, Docker containers? .
61 Answers
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Finding quaternion representing the rotation from one vector to another
I have two vectors u and v. Is there a way of finding a quaternion representing the rotation from u to v?
7 Answers
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App Inventor 2 AI伴侣有电脑版的吗? - App Inventor 2 中文网 - 清泛网 - 专注C/C++及内核技术
...扰、或商业模拟器安装不了，推荐使用AI2Starter模拟器。
Q & A
Q：AI2Starter模拟器可以调整分辨率吗？
A：可以，通过脚本可调整模拟器分辨率。最新版模拟器使用了三星手机样式，屏幕及分辨率较高。
Q：商业模拟器如何使用...
How to trick an application into thinking its stdout is a terminal, not a pipe
...
Aha!
The script command does what we want...
script --return --quiet -c "[executable string]" /dev/null
Does the trick!
Usage:
script [options] [file]
Make a typescript of a terminal session.
Options:
-a, --append append the output
-c, --command <command> ...
App Inventor 2 连接方式：AI伴侣、模拟器、USB · App Inventor 2 中文网
...扰、或商业模拟器安装不了，推荐使用AI2Starter模拟器。
Q & A
Q：AI2Starter模拟器可以调整分辨率吗？
A：可以，通过脚本可调整模拟器分辨率。最新版模拟器使用了三星手机样式，屏幕及分辨率较高。
Q：商业模拟器如何使用...
How to break a line of chained methods in Python?
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You could use additional parenthesis:
subkeyword = (
Session.query(Subkeyword.subkeyword_id, Subkeyword.subkeyword_word)
.filter_by(subkeyword_company_id=self.e_company_id)
.filter_by(subkeyword_word=subkeyword_word)
.filter_by(subkeyword_active=True)
.o...
Hidden Features of MySQL
...RY KEY:
There can be only one AUTO_INCREMENT column per table, it must be indexed, and it cannot have a DEFAULT value
KEY is normally a synonym for INDEX. The key attribute PRIMARY KEY can also be specified as just KEY when given in a column definition. This was implemented for compatibility with ...