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How to get consolidated count of delimiter occurrence

I have a requirement to fetch the count the occurrence of '|' in each line of a file then match the count with given inputcount, needs to throw exception when the count is wrong.
Say if the inputcount=3 and the file has following content
s01|test|aaa|hh
S02|test|bbb
so3|test|ccc|oo
then exception should get thrown on executing the line 2 and it should exit the file.
Tried below Awk command to fetch the count for each lines, but I was not sure how to compare and throw the exception, when it not matches
awk ' {print (split($0,a,"\|")-1) }' test.dat
Can anyone please help me with it?

You may use this awk:
awk -v inputcount=3 -F '\\|' 'NF && NF != inputcount+1 {exit 1}' file &&
echo "good" || echo "bad"
Details:
-F '\\|' sets | as input field separator
NF != inputcount+1 will return true if any line doesn't have inputcount pipe delimiters.

$ inputcount=3
$ awk -v c="$inputcount" 'gsub(/\|/,"&") != c{exit 1}' file
$ echo $?
1

As you also tagged the post with python I will write a python answer that could be a simple script.
The core is:
with open(filename) as f:
for n, line in enumerate(f):
if line.count("|") != 3:
print(f"Not valid file at line {n + 1}")
Than you can add some boilerplate:
import fileinput
import sys
with fileinput.input() as f:
for n, line in enumerate(f):
if line.count("|") != 3:
print(f"Not valid file at line {n + 1}")
sys.exit(1)
And with fileinput you can accept almost any sort of input: see Piping to a python script from cmd shell

Maybe try
awk -F '[|]' -v cols="$inputcount" 'NF != cols+1 {
print FILENAME ":" FNR ":" $0 >"/dev/stderr"; exit 1 }' test.dat
The -F argument says to split on this delimiter; the number of resulting fields NF will be one more than there are delimiters, so we scream and die when that number is wrong.

Passing Python variable as argument to shell script

I have a python code in which I need to run a shell script by passing arguments. Below is my code
#!/usr/bin/env python3
import subprocess
import os
import sys
filename=sys.argv[1]
subprocess.call(['bash','./shell.sh',filename])
print("Successfully completed")
Here I am trying to get an input as an argument while running ./file.py (filename) .But If I try to pass that as an argument to the shell script I am not able exceute the prograam.
Also I tried the code below
#!/usr/bin/env python3
import subprocess
import shlex
import sys
filename=sys.argv[1]
subprocess.call(shlex.split('./shell2.sh filename'))
For the above code I am getting error like this:
awk: fatal: cannot open file `filename' for reading (No such file or directory)
My script code:
file=$1
awk '{
if($0 ~ /LogType/){
if(hold ~ /LogType:stderr/){
print hold;
}
hold=$0
}else{
if($0 ~ /ERROR/ || $0 ~/WARN/){hold=hold "\n" $0 ": line " NR}else{hold=hold "\n" $0}
}
}END{
if(hold ~ /LogType:stderr/){
print hold
}
}' $file | sed -n -e 's/^.*LogType:\(stderr\)$/\1/p' \
-e 's/^.*Log Upload Time :\(.*\)/\1/p' \
-e 's/^.*LogLength:\(.*\)$/\1/p' \
-e 's/^.*\(ERROR\|WARN\).*$/\0/p'
How should I pass an input value to a shell script.Kindly help me to solve this issue .Thanks a lot!

Execute chained bash commands including multiple pipes and grep in Python3

I have to use the below bash command in a python script which includes multiple pip and grep commands.
grep name | cut -d':' -f2 | tr -d '"'| tr -d ','
I tried to do the same using subprocess module but didn't succeed.
Can anyone help me to run the above command in Python3 scripts?
I have to get the below output from a file file.txt.
Tom
Jack
file.txt contains:
"name": "Tom",
"Age": 10
"name": "Jack",
"Age": 15
Actually I want to know how can run the below bash command using Python.
cat file.txt | grep name | cut -d':' -f2 | tr -d '"'| tr -d ','

This works without having to use the subprocess library or any other os cmd related library, only Python.
my_file = open("./file.txt")
line = True
while line:
line = my_file.readline()
line_array = line.split()
try:
if line_array[0] == '"name":':
print(line_array[1].replace('"', '').replace(',', ''))
except IndexError:
pass
my_file.close()

If you not trying to parse a json file or any other structured file for which using a parser would be the best approach, just change your command into:
grep -oP '(?<="name":[[:blank:]]").*(?=",)' file.txt
You do not need any pipe at all.
This will give you the output:
Tom
Jack
Explanations:
-P activate perl regex for lookahead/lookbehind
-o just output the matching string not the whole line
Regex used: (?<="name":[[:blank:]]").*(?=",)
(?<="name":[[:blank:]]") Positive lookbehind: to force the constraint "name": followed by a blank char and then another double quote " the name followed by a double quote " extracted via (?=",) positive lookahead
demo: https://regex101.com/r/JvLCkO/1

Bash to Python: flatten directory tree

On Unix-like systems I use this script, which I'd like some help on porting to Python for execution on Windows hosts:
#!/bin/bash
SENTINEL_FILENAME='__sentinel__'
SENTINEL_MD5_CHECKSUM=''
SENTINEL_SHA_CHECKSUM=''
function is_directory_to_be_flattened() {
local -r directory_to_consider="$1"
local -r sentinel_filepath="${directory_to_consider}/${SENTINEL_FILENAME}"
if [ ! -f "${sentinel_filepath}" ]; then
return 1
fi
if [[
"$(
md5 "${sentinel_filepath}" \
| awk '{ print $NF }' 2> /dev/null
)" \
== "${SENTINEL_MD5_CHECKSUM}"
&& \
"$(
shasum -a 512 "${sentinel_filepath}" \
| awk '{ print $1 }' 2> /dev/null
)" \
== "${SENTINEL_SHA_CHECKSUM}"
]]; then
return 0
else
return 1
fi
}
function conditionally_flatten() {
local -r directory_to_flatten="$1"
local -r flatten_into_directory="$2"
if is_directory_to_be_flattened "${directory_to_flatten}"; then
if [ ! -d "${flatten_into_directory}" ]; then
mkdir -v "${flatten_into_directory}"
fi
for file_to_move in $(find ${directory_to_flatten} -type f -maxdepth 1); do
mv \
-v \
-n \
"${file_to_move}" \
"${flatten_into_directory}"
done
fi
}
function flatten_directory() {
local -r directory_to_flatten="$1"
local -r descend_depth="$2"
local -r flattened_directory="${directory_to_flatten}/__flattened__"
if [ ! -d "${directory_to_flatten}" ]; then
printf "The argument '%s' does not seem to be a directory.\n" \
"${directory_to_flatten}" \
>&2
return
fi
find "${directory_to_flatten}" \
-type d \
-maxdepth "${descend_depth}" \
| \
while read directory_path; do
conditionally_flatten \
"${directory_path}" \
"${flattened_directory}"
done
}
n_arguments="$#"
if [ "${n_arguments}" -eq 1 ]; then
flatten_directory "$1" '1' # maybe use a constant, not a "magic #" here?
else
echo usage: "$0" /path/to/directory/to/flatten
fi
unset is_directory_to_be_flattened
unset conditionally_flatten
unset flatten_directory
How would you port this to Win Python? I am a beginner in both Python and Bash scripting..
Feel free to upgrade my implementation as you port it if you find it lacking in any way too, with a justification please. This is not "Code Review" but a "thumbs up/thumbs down" on my effort in Bash would give me a sense of whether I am improving or I should change the way I study altogether...
Here we go, my attempt in Python: (criticise it hard if need be, it's the only way for me to learn!)
#!/usr/bin/env python2.7
import sys
import os
import shutil
SENTINEL_FILENAME=''
SENTINEL_MD5_CHECKSUM=''
SENTINEL_SHA_CHECKSUM=''
DEFAULT_DEPTH = 1
FLATTED_DIRECTORY_NAME = '__flattened__'
def is_directory_to_be_flattened(directory_to_consider):
sentinel_location = os.path.join(directory_to_consider, SENTINEL_FILENAME)
if not os.path.isfile(sentinel_location):
return False
import hashlib
with open(sentinel_location) as sentinel_file:
file_contents = sentinel_file.read()
return (hashlib.md5(file_contents).hexdigest() == SENTINEL_MD5_CHECKSUM
and hashlib.sha512(file_contents).hexdigest() == SENTINEL_SHA_CHECKSUM)
def flatten(directory, depth, to_directory, do_files_here):
if depth < 0:
return
contained_filenames = [f for f in os.listdir(directory)]
if do_files_here:
for filename in contained_filenames:
if filename == SENTINEL_FILENAME:
continue
filepath = os.path.join(directory, filename)
if not os.path.isfile(filepath):
continue
file_to = os.path.join(to_directory, filename)
if not os.path.isdir(to_directory):
os.makedirs(to_directory)
if not os.path.isfile(file_to):
print "Moving: '{}' -> '{}'".format(filepath, file_to)
shutil.move(filepath, file_to)
else:
sys.stderr.write('Error: {} exists already.\n'.format(file_to))
next_depth = depth - 1
for subdirectory in (d for d in contained_filenames if os.path.isdir(d)):
if is_directory_to_be_flattened(subdirectory):
flatten(subdirectory, next_depth, to_directory, True)
def flatten_directory(to_flatten, depth):
to_directory = os.path.join(to_flatten, FLATTED_DIRECTORY_NAME)
if not os.path.isdir(to_flatten):
sys.stderr.write(
'The argument {} does not seem to be a directory.\n'.format(
to_flatten))
return
flatten(to_flatten, depth, to_directory, False)
def main():
if len(sys.argv) == 2:
flatten_directory(sys.argv[1], DEFAULT_DEPTH)
else:
print 'usage: {} /path/to/directory/to/flatten'.format(sys.argv[0])
if __name__ == '__main__':
main()
Although it's obvious from the code, the intent is:
Start at a given directory
Descend up to a certain depth
Consider subdirectories and move all files therein if and only if:
The directory contains a "sentinel file" with a given filename
The sentinel file is actually a sentinel file, not just a file renamed to the same name
Collate files in a __flattened__ directory under the directory in which the search started

Most file dealing functions in Python are in the module "os" - therein you will find
os.rename (for renaming or moving a directoruy entry), os.listdir - which gives you a listing of filenames in the directory, passed as first arg, os.walk - to recursively walk through a directory structure, os.path.walk, to do the same, but with a callback, os.path.exists, os.path.isdir, os.mkdir, are others that might be handy.
For a "quick and dirty" translation you might also cehck "os.system". which allows you to execute a shell command just like it was typed in the shell, and os.popen - which allows access to stdin and stdout of said process. A more carefull translation, tough, would require using anothe module: "subprocess" which can give one full control of a shell command executed as sub process (although if you need find, for example, it won't be available on windows)
Other moduless of interest are sys (sys.argv are the arguments passed to the script) and shutil (with things like copy, rmtree and such)
Your script does some error checking, and it is trivial, given the above funcion names in "os" and basic Python to add them - but a short "just do it" script in Python could be just:
import os, sys
dir_to_flatten = sys.argv[1]
for dirpath, dirnames, filenames in os.walk(dir_to_flatten):
for filename in filenames:
try:
os.rename(os.path.join(dirpath, filename), os.path.join(dir_to_flatten, filename))
except OSError:
print ("Could not move %s " % os.path.join(dirpath, filename))

How do I convert this bash loop to python?

How would I do file reading loop in python? I'm trying to convert my bash script to python but have never written python before. FYI, the reason I am read reading the file after a successful command competition is to make sure it reads the most recent edit (say if the URLs were reordered).
Thanks!
#!/bin/bash
FILE=$1
declare -A SUCCESS=()
declare -A FAILED=()
for (( ;; )); do
# find a new link
cat "$FILE" > temp.txt
HASNEW=false
while read; do
[[ -z $REPLY || -n ${SUCCESS[$REPLY]} || -n ${FAILED[$REPLY]} ]] && continue
HASNEW=true
break
done < temp.txt
[[ $HASNEW = true ]] || break
# download
if axel --alternate --num-connections=6 "$REPLY"; then
echo
echo "Succeeded at $DATETIME downloading following link $REPLY"
echo "$DATETIME Finished: $REPLY" >> downloaded-links.txt
echo
SUCCESS[$REPLY]=.
else
echo
echo "Failed at $DATETIME to download following link $REPLY"
echo "$DATETIME Failed: $REPLY" >> failed-links.txt
FAILED[$REPLY]=.
fi
# refresh file
cat "$FILE" > temp.txt
while read; do
[[ -z ${SUCCESS[REPLY]} ]] && echo "$REPLY"
done < temp.txt > "$FILE"
done
This is what I've got so far which is working, and I can't figure out how to make it read the top line of the file after every successful execution of the axel line like the bash script does. I'm open to other options on the subprocess call such as threading, but I'm not sure how to make that work.
#!/usr/bin/env python
import subprocess
from optparse import OptionParser
# create command line variables
axel = "axel --alternate --num-connections=6 "
usage = "usage: %prog [options] ListFile.txt"
parser = OptionParser(usage=usage)
parser.add_option("-s", "--speed", dest="speed",
help="speed in bits per second i.e. 51200 is 50kps", metavar="speedkbps")
(opts, args) = parser.parse_args()
if args[0] is None:
print "No list file given\n"
parser.print_help()
exit(-1)
list_file_1 = args[0]
try:
opts.speed
except NoSpeed:
with open(list_file_1, 'r+') as f:
for line in f:
axel_call = axel + "--max-speed=" + opts.speed + " " + line
# print ("speed option set line send to subprocess is: " + axel_call)
subprocess.call(axel_call, shell=True)
else:
with open(list_file_1, 'r+') as f:
for line in f:
axel_call = axel + line
# print ("no speed option set line send to subprocess is:" + axel_call)
subprocess.call(axel_call, shell=True)

Fully Pythonic way to read a file is the following:
with open(...) as f:
for line in f:
<do something with line>
The with statement handles opening and closing the file, including if an exception is raised in the inner block. The for line in f treats the file object f as an iterable, which automatically uses buffered IO and memory management so you don't have to worry about large files.
There should be one -- and preferably only one -- obvious way to do it.

A demonstration of using a loop to read a file is shown at http://docs.python.org/tutorial/inputoutput.html#reading-and-writing-files