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How to deal with SettingWithCopyWarning in Pandas?
...copy. [see GH5390 and GH5597 for background discussion.]
df[df['A'] > 2]['B'] = new_val # new_val not set in df
The warning offers a suggestion to rewrite as follows:
df.loc[df['A'] > 2, 'B'] = new_val
However, this doesn't fit your usage, which is equivalent to:
df = df[df['A'] > ...
How can I debug git/git-shell related problems?
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217
For even more verbose output use following:
GIT_CURL_VERBOSE=1 GIT_TRACE=1 git pull origin ma...
Can dplyr package be used for conditional mutating?
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220
Use ifelse
df %>%
mutate(g = ifelse(a == 2 | a == 5 | a == 7 | (a == 1 & b == 4), 2,
...
程序员之网络安全系列（二）：如何安全保存用户密码及哈希算法 - 更多技术 ...
...唯一且极其紧凑的数值表示形式. 典型的哈希算法包括 MD2、MD4、MD5 和 SHA-1
Hash算法是给消息生成摘要，那么什么是摘要呢？
举个例子： > 比如你给你女朋友写了一封邮件，确保没被人改过，你可以生成这样一份摘要 “第50个字...
Python creating a dictionary of lists
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286
You can use defaultdict:
>>> from collections import defaultdict
>>> d = de...
Ruby 2.0.0p0 IRB warning: “DL is deprecated, please use Fiddle”
...ions of Ruby, removed all of my gems
(including Rails), and installed Ruby 2.0. In other words, a totally clean re-install. Upon starting IRB, I received this message:
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Operation on every pair of element in a list
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233
Check out product() in the itertools module. It does exactly what you describe.
import itert...
How to split a column into two columns?
... row
0 00000 UNITED STATES
1 01000 ALABAMA
2 01001 Autauga County, AL
3 01003 Baldwin County, AL
4 01005 Barbour County, AL
df = pd.DataFrame(df.row.str.split(' ',1).tolist(),
columns = ['flips','row'])
flips ...
Unicode与UTF-8互转(C语言实现) - C/C++ - 清泛网 - 专注C/C++及内核技术
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位(bit)有0和1两种状态, 因此八个二进制位就可以组合出 256种状态, 这被称为一个字
节(byte). 也就是说, 一个字节一共可以用来表示256种不同的状态, 每一个状态对应一
个符号, 就是256个符号, 从 0000000到11111111.
上个世纪60年代...