A Technical I.T./DevOps Blog
Problem scenario
You want to be able to say you ran a machine learning program. You know some Python basic. What do you do to write a very simple machine learning program?
Solution
Prerequisite
This assumes that pip has been installed. If you need assistance see this posting.
Procedures
1.
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Problem scenario
Your Java program returns this message: “com.mysql.jdbc.exceptions.MySQLSyntaxErrorException: Unknown database foobar”
What should you do?
Possible solution #1
Are you using Amazon Aurora? AWS has a MySQL PaaS offering. You may have a section of the Java code that looks like this:
Connection con=DriverManager.getConnection(“jdbc:mysql://foobar-us-west-2b.abcdefghijk.us-west-2.rds.amazonaws.com:3306/foobar”)
Remove the last “foobar” from the end. The connection string should look like this for Aurora databases:
jdbc:mysql://foobar-us-west-2b.abcdefghijk.us-west-2.rds.amazonaws.com:3306/foobar
Recompile the program.
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Question
Python supports the creation of new threads for [bound or unbound] functions. They can help with multiprocessing. New threads are ideal for non-blocking operations like serving a GUI. If you want a server to begin certain operations in parallel with others, you may want to use new threads as opposed to new processes (which can provide the same parallel processing benefit).
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Continue reading “In Python, What Are Some Advantages with Calling a Function or as a New Thread?”
Question
Python supports the creation of new threads for [bound or unbound] functions. They can help with multiprocessing. If you want a server to begin certain operations in parallel with others, you may want to use new processes as opposed to new threads. Both threads and processes can provide the same parallel processing benefit. What are some disadvantages of using a thread to call a function?
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Continue reading “In Python, What Are Some Disadvantages with Calling a Function as a New Thread?”
Problem scenario
You want to install pip to work with Python packages and Python features. How do you install this on an Ubuntu or Debian Linux server?
Solution
Run these commands:
sudo apt-get -y update
sudo apt-get -y install python-pip
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Continue reading “How Do You Install pip on an Ubuntu or Debian Server?”
Problem scenario
You run a shell or bash script but you receive an error message such as one of the following:
$’\r’: command not found
line:55 syntax error: unexpected end of file
Solution
Did you download the file from the internet directly to the Unix system? The root cause could be that there are invisible characters in the file.
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Continue reading “How Do You Troubleshoot Error Messages in a Bash Script?”
Problem scenario
Many Azure commands are failing. You installed the Azure module. But commands related to “Azure Storage” all return “not recognized as the name of a cmdlet, function, script file or operable program.”
You see messages like this:
New-AzureStorageAccount : A parameter cannot be found that matches parameter name ‘ResourceGroupName’.
At line:4 char:25
+ New-AzureStorageAccount -ResourceGroupName “contIntGroup” -AccountNam …
+ ~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidArgument: (:) [New-AzureStorageAccount], …
Problem scenario
You prefer Python to Ruby for certain tasks, and you want to have a way of testing your configuration management tools. You want to use Testinfra to accomplish this (https://testinfra.readthedocs.io/en/latest/). You want to install Testinfra to test it out. What do you do?
Solution
Prerequisites
i. You must have pip3 installed on the server.
…
Continue reading “How Do You Use Testinfra (the Python module)?”
Problem scenario
You have seen Python functions defined using the self keyword. You want to test it out. How do you do this?
Solution
First of all, self is NOT a keyword in Python. Yes, you should probably use the word “self” when it is invoked. This is a well-accepted convention. It may be an unwritten rule. But you do not need to use the word “self”.
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Problem scenario
You want to write a program that will test if a pattern is in another word. You are looking for the SQL equivalent of “contains” in Python. How do you test if a string is a substring of another word?
Solution
Use this program:
# Change “micro” and “microsoft” to the substring and string to be searched respectively:
a = “micro”
b = “microsoft”
if a in b:
print(a + ” is in ” + b)
else:
print(a + ” is NOT in ” + b) …