Tutorial by Examples: r

this will accept any type with a method named GetLength that takes nothing and returns an int: ((^a : (static member GetLength : int) ()))

Such a group is made of radiobuttons that share a control variable so that no more than one can be selected. # control variable var = tk.IntVar(parent, 0) # group of radiobuttons for i in range(1,4): tk.Radiobutton(parent, text='Choice %i' % i, value=i, variable=var).pack() tk.Button(p...

Yank all lines containing TODO into a register by using append operation :global/TODO/yank A Here, we are searching for a TODO keyword globally, yanking all lines into register a (A register appends all lines to a register). NOTE: It is in general a good practice to clear a register before perf...

If constraints for std::promise and std::future are not met an exception of type std::future_error is thrown. The error code member in the exception is of type std::future_errc and values are as below, along with some test cases: enum class future_errc { broken_promise = /* the t...

Getting a GA Account: If you don’t have an Analytics account, create one. If you do have an Analytics account, sign in. Both options are available at google.com/analytics Setting up a property in your Analytics account: A property represents your website or app where the data gets aggrega...

The gross majority of the time a SyntaxError which points to an uninteresting line means there is an issue on the line before it (in this example, it's a missing parenthesis): def my_print(): x = (1 + 1 print(x) Returns File "<input>", line 3 print(x) ^...

To complete this objective following tasks are required. Foreach Loop Container: To iterate over a user configured directory for files. Expression Task: To update a variable if file exists. Steps First goto Solution Explorer double click on Project.params and create a parameter FolderPat...

The below coordinator job will trigger coordinator action once in a day that executes a workflow. The workflow has a shell script that moves input to output. <coordinator-app name="log_process_coordinator" frequency="${coord:days(1)}" start="2017-04-29T06:00Z" ...

<workflow-app xmlns="uri:oozie:workflow:0.4" name="shell-wf"> <start to="shell-node"/> <action name="shell-node"> <shell xmlns="uri:oozie:shell-action:0.2"> <job-tracker>${jobTracker}</job-tracker> <name-n...

nameNode=hdfs://namenode:port start=2016-04-12T06:00Z end=2017-02-26T23:25Z jobTracker=yourjobtracker poolName=yourpool oozie.coord.application.path=${nameNode}/hdfs_path/coord_job_example/coord workflowAppUri=${oozie.coord.application.path} myscript=myscript.sh myscriptPath=${oozie.coord.ap...

inputDir=${1} outputDir=${2} hadoop fs -mkdir -p ${outputDir} hadoop fs -cp ${inputDir}/* ${outputDir}/

Copy the script, coordinator.xml and workflow.xml into HDFS. coordinator.xml must be present in the directory specified by oozie.coord.application.path in job.properties. workflow.xml should be present in the directory specified by workflowAppUri. Once everything is in place, run the below command f...

Table/Column Names Two common ways of formatting table/column names are CamelCase and snake_case: SELECT FirstName, LastName FROM Employees WHERE Salary > 500; SELECT first_name, last_name FROM employees WHERE salary > 500; Names should describe what is stored in their object. Th...

Content of file.json (one JSON object per line): {"A": 1, "B": 2} {"A": 3, "B": 4} How to read directly from a local file: pd.read_json('file.json', lines=True) # Output: # A B # 0 1 2 # 1 3 4

Creating Express Web Server Express server came handy and it deeps through many user and community. It is getting popular. Lets create a Express Server. For Package Management and Flexibility for Dependency We will use NPM(Node Package Manager). Go to the Project directory and create package....

if len(sys.argv) != 4: # The script name needs to be accounted for as well. raise RuntimeError("expected 3 command line arguments") f = open(sys.argv[1], 'rb') # Use first command line argument. start_line = int(sys.argv[2]) # All arguments come as strings, so need to ...

# The name of the executed script is at the beginning of the argv list. print('usage:', sys.argv[0], '<filename> <start> <end>') # You can use it to generate the path prefix of the executed program # (as opposed to the current module) to access files relative to that, # which...

# Error messages should not go to standard output, if possible. print('ERROR: We have no cheese at all.', file=sys.stderr) try: f = open('nonexistent-file.xyz', 'rb') except OSError as e: print(e, file=sys.stderr)

def main(): if len(sys.argv) != 4 or '--help' in sys.argv[1:]: print('usage: my_program <arg1> <arg2> <arg3>', file=sys.stderr) sys.exit(1) # use an exit code to signal the program was unsuccessful process_data()

A common problem with remote services is rate limiting. The remote service allows us to send only a limited number of requests or amount of data per time period. In RxJS 5 a very similar functionality is provided by the bufferTime operator and especially if we leave the second parameter unspecified...