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linux - How does "cat << EOF" work in bash?

I needed to write a script to enter multi-line input to a program (psql). After a bit of googling, I found the ... exactly do? And is there a man page for it? Question&Answers:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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database - Difference between partition key, composite key and clustering key in Cassandra?

I have been reading articles around the net to understand the differences between the following key types. But ... , partition key, composite key clustering key Question&Answers:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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fonts - How do I make an attributed string using Swift?

I am trying to make a simple Coffee Calculator. I need to display the amount of coffee in grams. The "g" ... about this the wrong way. Any help is appreciated! Question&Answers:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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android - How can I create a keystore?

What are the steps to create a keystore for android? I need to use google maps in my app and I don't know ... steps (I didn't understand it from the guides). Question&Answers:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c++ - Is std::vector so much slower than plain arrays?

I've always thought it's the general wisdom that std::vector is "implemented as an array," blah blah blah. Today I ... to 4 seconds). This is really huge, IMO. Question&Answers:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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objective c - How to easily resize/optimize an image size with iOS?

My application is downloading a set of image files from the network, and saving them to the local iPhone disk. ... change the quality setting of a JPEG image? Question&Answers:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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What does "hashable" mean in Python?

I tried searching internet but could not find the meaning of hashable. When they say objects are hashable or hashable objects what does it mean? Question&Answers:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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Getting output of system() calls in Ruby

If I call a command using Kernel#system in Ruby, how do I get its output? system("ls") Question&Answers:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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security - .NET obfuscation tools/strategy

Closed. This question is opinion-based. It is not currently accepting answers. Question&Answers:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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Laravel 5 - How to access image uploaded in storage within View?

I have got user's avatars uploaded in Laravel storage. How can I access them and render them in a view? The ... show them if they are in the /storage folder? Question&Answers:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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asp.net - How to create JSON string in C#

I just used the XmlWriter to create some XML to send back in an HTTP response. How would you create a ... JSON string and them format your response as JSON? Question&Answers:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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Writing data into CSV file in C#

I am trying to write into a csv file row by row using C# language. Here is my function string first = reader[0]. ... can I write all the rows in the csv file? Question&Answers:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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lookup - How to do vlookup and fill down (like in Excel) in R?

I have a dataset about 105000 rows and 30 columns. I have a categorical variable that I would like to assign it ... 3 Single 2 Apartment 4 Apartment 4 Row 3 Question&Answers:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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group concat - MySQL and GROUP_CONCAT() maximum length

I'm using GROUP_CONCAT() in a MySQL query to convert multiple rows into a single string. However, the maximum ... a multiple row query into a single string? Question&Answers:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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c# - Why can't I define a default constructor for a struct in .NET?

In .NET, a value type (C# struct) can't have a constructor with no parameters. According to this ... enough to prevent definition of a default constructor. Question&Answers:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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javascript - How do I upload a file with the JS fetch API?

I am still trying to wrap my head around it. I can have the user select the file (or even multiple) with the ... content-type header? }).then(/* whatever */); Question&Answers:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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102 views

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c# - Should I use int or Int32

In C#, int and Int32 are the same thing, but I've read a number of times that int is preferred over Int32 with ... given. Is there a reason, and should I care? Question&Answers:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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382 views

1 answer

Using the slash character in Git branch name

I'm pretty sure I saw somewhere in a popular Git project the branches had a pattern like "feature/xyz". ... create a branch in Git with the slash character? Question&Answers:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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429 views

1 answer

bytearray - hexadecimal string to byte array in python

I have a long Hex string that represents a series of values of different types. I wish to convert this Hex ... out and convert it into its proper data type. Question&Answers:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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Python None comparison: should I use "is" or ==?

My editor warns me when I compare my_var == None, but no warning when I use my_var is None. I did a test in ... preferred. Is this the case, and if so, why? Question&Answers:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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140 views

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windows - "python" not recognized as a command

I just downloaded and installed Python 2.7.2 to my laptop and I am trying to run some sample programs. My ... is? The installer placed Python at C:Python27. Question&Answers:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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445 views

1 answer

c++ - Converting std::__cxx11::string to std::string

I use c++11, but also some libraries that are not configured for it, and need some type conversion. In ... const&, unsigned long, H5::DataType const&) const' Question&Answers:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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455 views

1 answer

rust - How to include a module from another file from the same project?

By following this guide I created a Cargo project. src/main.rs fn main() { hello::print_hello(); } mod ... the current project into the project's main file? Question&Answers:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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90 views

1 answer

c++ - What is IACA and how do I use it?

I've found this interesting and powerful tool called IACA (the Intel Architecture Code Analyzer), but I have ... Use it to analyze code in x86 assembler? Question&Answers:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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333 views

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database - Throw an error preventing a table update in a MySQL trigger

If I have a trigger before the update on a table, how can I throw an error that prevents the update on that table? Question&Answers:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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101 views

1 answer

Facebook API error 191

I'm trying to integrate my project with Facebook. I'm taking baby steps at first and just trying to login, get ... application settings, but I can't see what! Question&Answers:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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979 views

1 answer

testing - Switch tabs using Selenium WebDriver with Java

Using Selenium WebDriver with JAVA. I am trying to automate a functionality where I have to open a new tab ... tabs in same window, window handle remains same) Question&Answers:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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134 views

1 answer

r - Remove part of string after "."

I am working with NCBI Reference Sequence accession numbers like variable a: a <- c("NM_020506.1","NM_020519.1" ... this variable. Can anyone help me with this? Question&Answers:os...

asked Oct 17, 2021 in Technique[技术] by 深蓝 (71.8m points)

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