mrjob | Run MapReduce jobs on Hadoop or Amazon Web Services
kandi X-RAY | mrjob Summary
kandi X-RAY | mrjob Summary
Run MapReduce jobs on Hadoop or Amazon Web Services
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Top functions reviewed by kandi - BETA
- Print the summary of the cluster
- Strip microseconds
- Calculate a percentage value
- Return boto3 - compatible datetime
- Return statistics for each cluster
- Convert a cluster to a dictionary
- Summarize a cluster
- Return usage data for cluster
- Configure command line arguments
- Execute a single step on Spark
- Creates an argument parser
- Yield cluster clusters
- Resolve EMR job options
- Sorts lines with sort
- Runs ssh on all connected nodes
- Terminate the EMR jobs
- Return the arguments for the Spark job script
- Invoke the task function
- Run a single partition
- Generate the linkback node
- Find jobs that are long running
- Count the number of ngrams for each document
- Score documents by ngram
- List files in a directory
- Score multiple documents
- Parse a document
mrjob Key Features
mrjob Examples and Code Snippets
Lines of Code : 15License : Permissive (MIT)
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pip install -r requirements.txt
virtualenv --no-site-packages env/
source env/bin/activate
pip install -r requirements.txt
./get-data.sh
python tag_counter.py --conf-path mrjob.conf --no-output --output-dir out input/test-1.warc
# or 'local' simulates more features of Hadoop such as counters
python tag_counter.py -r local --conf-path mrjob.conf --no-output --output-dir import re
from collections import defaultdict
from itertools import combinations
from mrjob.job import MRJob
from mrjob.step import MRStep
WORD_RE = re.compile(r"[\w']+")
class MRRelativeFreq(MRJob):
denoms = defaultdict(int)
def reducer(self, key, values):
totalprice, totalqty = 0,0
for value in values:
totalprice += (value[0])
totalqty += value[1]
average = round(totalprice/totalqty,2)
yield key, averagedef mapper(self, _, line):
review = json.loads(line)
def mapper(self, _, line):
stop_words = set(["to", "a", "an", "the", "for", "in", "on", "of", "at", "over", "with", "after", "and", "from", "new", "us", "by", "as", "man", "up", "says", "in", "out", "is", "be", "are", "not", "pm", "am""""The classic MapReduce job: count the frequency of words.
"""
from mrjob.job import MRJob
import re
WORD_RE = re.compile(r"[\w']+")
class MRWordFreqCount(MRJob):
def mapper(self, _, line):
for word in WORD_RE.findall(linefrom datetime import datetime
import json
import argparse
parser = argparse.ArgumentParser()
parser.add_argument("-t", "--time", help = "Output file")
args, unknown = parser.parse_known_args()
class Calculate(MRJob):
def configure_arclass MR3Nums(MRJob):
def mapper(self, _, line):
sequence_length = 3
words = line.strip().split()
for i in range(len(words) - sequence_length + 1):
yield " ".join(words[i:(i+sequence_length)]), Community Discussions
Trending Discussions on mrjob
QUESTION
i am new in python and i want to use MrJob package for countind relative frequency of pair words i wrote below code but it doesn't make correct output. can you plz help me with my mistakes? 𝑓(𝐴|𝐵) = 𝑐𝑜𝑢𝑛𝑡(𝐴, 𝐵)/𝑐𝑜𝑢𝑛𝑡(𝐵)=𝑐𝑜𝑢𝑛𝑡(𝐴, 𝐵)/∑A' 𝑐𝑜𝑢𝑛𝑡(𝐴′ , 𝐵)
...ANSWER
Answered 2021-Dec-19 at 21:44You will need an intermediate data structure, in this case a defaultdict to count the total of times the word appears.
QUESTION
I have a .csv source file in the form of:
Xxx,yyy,zzz,uuuu,iii,www,qqq,aaa,rrr,30.95,1,MATT,MORAL,CUREPIPE
Xxx,yyy,zzz,uuuu,iii,www,qqq,aaa,rrr,19.95,1, MATT,MORAL, CUREPIPE
Xxx,yyy,zzz,uuuu,iii,www,qqq,aaa,rrr,89.95,1,LELA,SMI,HASSEE
Xxx,yyy,zzz,uuuu,iii,www,qqq,aaa,rrr,54.50,1,LELA,SMI,HASSEE
Xxx,yyy,zzz,uuuu,iii,www,qqq,aaa,rrr,19.95,2,TOM, SON,FLACQ
Xxx,yyy,zzz,uuuu,iii,www,qqq,aaa,rrr,19.95,1,DYDY,ARD,PLOUIS
Xxx,yyy,zzz,uuuu,iii,www,qqq,aaa,rrr,22.00,1,DYDY,ARD, PLOUIS
Xxx,yyy,zzz,uuuu,iii,www,qqq,aaa,rrr,19.95,1,DYDY,ARD, PLOUIS
Xxx,yyy,zzz,uuuu,iii,www,qqq,aaa,rrr,22.00,2,TAY,ANA,VACOAS
Xxx,yyy,zzz,uuuu,iii,www,qqq,aaa,rrr,35.00,3,TAY,ANA,VACOAS
I would like to calculate the average cost (price*qty/total qty) for each person using a combiner in MapReduce with the following result:
MATT MORAL 25.45
LELA SMI 72.225
TOM SON 19.95
DYDY ARD 20.36
TAY ANA 29.8
So I came up with the following code which is not working (giving me double the average). I do feel like I need to add an IF ELSE statement in the reducer to process the output of the combiner (unique keys) differently to the output of the mapper (duplicated keys):
...ANSWER
Answered 2021-Nov-26 at 13:13You shouldn't be weighting the totalprice in the reducer as you have already done that in the combiner -
QUESTION
I'm trying to use hadoop to get some statistics from a json file like average number of stars for a category or language with most reviews. To do this I am using mrjob, I found this code:
...ANSWER
Answered 2021-Nov-18 at 15:05For me was useful just to use json.loads, like:
QUESTION
def mapper(self, _, line):
stop_words = set(["to", "a", "an", "the", "for", "in", "on", "of", "at", "over", "with", "after", "and", "from", "new", "us", "by", "as", "man", "up", "says", "in", "out", "is", "be", "are", "not", "pm", "am", "off", "more", "less", "no", "how"])
(date,words) = line.strip().split(",")
word_list = words.split()
clean_words = [word for word in word_list if word not in stop_words]
clean_words.sort()
yield (date[0:4],clean_words)
ANSWER
Answered 2021-Nov-16 at 22:04Use a loop to yield each word separately.
QUESTION
I have the below code and get the word count but getting the first letter frequency of all the words I don't understand how to do this. If there are three words starting with C in the file I would expect the outcome to be "C 3". I don't need to distinguish between caps so 'a' and 'A' will be the counted the same.
...ANSWER
Answered 2021-Oct-31 at 08:40You can change the default example on https://pypi.org/project/mrjob/:
QUESTION
I am using Python mrjob to find the 10 longest words from a text file. I have obtained a result, but the result contains duplicate words. How do I obtain only unique words (ie. remove duplicate words)?
...ANSWER
Answered 2021-Oct-28 at 11:09Update reducer_find_longest_words to get only the unique elements. Note the use of list(set()).
QUESTION
Normally, if I want to define a command-line option for mrjob, I have to do like this:
...ANSWER
Answered 2021-May-16 at 02:02I found a workaround solution but I hope there will be a better way of doing this.
I have to define the argument again inside the mrjob class so it can recognize it:
QUESTION
Consider a file containing words separated by spaces; write a MapReduce program in Python, which counts the number of times each 3-word sequence appears in the file.
For example, consider the following file:
...ANSWER
Answered 2021-Apr-10 at 16:17The mapper is applied on each line, and should count each 3-word sequence, i.e. yield the 3-word sequence along with a count of 1.
The reducer is called with key and values, where key is a 3-word sequence and values is a list of counts (which would be a list of 1s). The reducer can simply return a tuple of the 3-word sequence and the total number of occurrences, the latter obtained via sum.
QUESTION
I'm trying to use mrJobs with a csv file. The problem is the csv file has input spanned over multiple lines.
Searching through the mrJob documentation, I think I need to write a custom protocol to handle the input.
I tried to write my own protocol below, multiLineCsvInputProtocol, but I am already getting an error: TypeError: a bytes-like object is required, not 'str'
Not going to lie in that I think I am over my head here.
Basically each new row of data in the multi-line csv file starts with a datestring. I want to read input line by line, spit each line on the commas, store the values in a list, and whenever a new line starts with a datestring, I want to yield the entire list to the first mapper.
(That or find some other better way to read multi-line csv input)
Can anyone help me get passed this error?
...ANSWER
Answered 2021-Mar-25 at 02:48According to the documentation of the mrjob, the line parameter of the read function has the type of bytestring, you are most likely getting that error because you are split-ting by ',' which is an str:
Writing custom protocols
A protocol is an object with methods read(self, line) and write(self, key, value). The read() method takes a bytestring and returns a 2-tuple of decoded objects, and write() takes the key and value and returns bytes to be passed back to Hadoop Streaming or as output.
Possible solutions:
- You can try splitting by
b',', which is a bytestring - You can decode the line before the splitting, like this:
line.decode().split(',', 1)(it's probably a good idea to specify the encoding)
QUESTION
I have a Hadoop 3.2.2 Cluster with 1 namenode/resourceManager and 3 datanodes/NodeManagers.
this is my yarn-site config
...ANSWER
Answered 2021-Mar-24 at 19:53I forgot to install mr_job on all nodes...
run this on all nodes fixed the problem:
pip3 install MRJob
Community Discussions, Code Snippets contain sources that include Stack Exchange Network
Vulnerabilities
No vulnerabilities reported
Install mrjob
You can use mrjob like any standard Python library. You will need to make sure that you have a development environment consisting of a Python distribution including header files, a compiler, pip, and git installed. Make sure that your pip, setuptools, and wheel are up to date. When using pip it is generally recommended to install packages in a virtual environment to avoid changes to the system.
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