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How to map and remove nil values in Ruby
I have a map which either changes a value or sets it to nil. I then want to remove the nil entries from the list. The list doesn't need to be kept.
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Null coalescing in powershell
...t throws The variable '$myval' cannot be retrieved because it has not been set..
– BrainSlugs83
Jul 3 '19 at 22:46
1
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Difference between `set`, `setq`, and `setf` in Common Lisp?
What is the difference between "set", "setq", and "setf" in Common Lisp?
6 Answers
6
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Print second last column/field in awk
I want to print the second last column or field in awk. The number of fields is variable. I know that I should be able to use $NF but not sure how it can be used.
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Pandas: Looking up the list of sheets in an excel file
...ry directory with the file name
directory_to_extract_to = os.path.join(settings.MEDIA_ROOT, file_name)
os.mkdir(directory_to_extract_to)
# Extract the xlsx file as it is just a zip file
zip_ref = zipfile.ZipFile(file_path, 'r')
zip_ref.extractall(directory_to_extract_to)
zip...
How to import multiple .csv files at once?
... try the following:
temp = list.files(pattern="*.csv")
list2env(
lapply(setNames(temp, make.names(gsub("*.csv$", "", temp))),
read.csv), envir = .GlobalEnv)
But again, it's often better to leave them in a single list.
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Discuz轻松生成sitemaps.xml网站地图 - 更多技术 - 清泛网 - 专注C/C++及内核技术
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PS：注意编码，选择自己DZ对应的编码，我自己用的是UTF-8版本DZ
<?php
if(!defined('IN_DISCUZ')) {
exit('Access Denied');
}
$filename='sitemaps.xml';
//以下五项根据具体情况修改即可
$cfg_updateperi='60';//协议文件更新周期的上限，单位为分...
Big-oh vs big-theta [duplicate]
It seems to me like when people talk about algorithm complexity informally, they talk about big-oh. But in formal situations, I often see big-theta with the occasional big-oh thrown in.
I know mathematically what the difference is between the two, but in English, in what situation would using big-oh...
Push existing project into Github
...a php project. Let's say that you have the index.php, contact.php and an assets folder with images, css, and fonts. You can do it this way (easy), but there are many options:
Option 1
Login to your github account and create the repo.
In the following screen you can copy it down where you need it i...
How to compute the similarity between two text documents?
...ts()
im = ax.imshow(values)
# We want to show all ticks...
ax.set_xticks(np.arange(len(x_labels)))
ax.set_yticks(np.arange(len(y_labels)))
# ... and label them with the respective list entries
ax.set_xticklabels(x_labels)
ax.set_yticklabels(y_labels)
# Rotate the ti...