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Print variable to txt file [duplicate]

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Print string to text file
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Closed 2 years ago.
I am working on making a separate txt file with the output data from str(velocity). Currently it prints fine in the terminal but no success in printing it to a txt file.
import socket
import numpy as np
import pigpio
#------------------------Definingfunctions and variables ------------------#
pi = pigpio.pi()
pi.set_mode(21,pigpio.INPUT)
pulseDegrees = 2*np.pi/38
T_old = 0
count = 0
def cbf(g ,L ,t):
T_new = t
global velocity, T_old
velocity = pulseDegrees/(T_new-T_old)*(1/0.000001)
print(str(velocity))
T_old = T_new
def sendData():
conn.recv (1024)
conn.send(str(velocity).encode('UTF-8'))
#--------------------------Communication--------------------#
# The units ipaddress
print ("Awaiting connection")
port=5555
s=socket.socket()
s.bind(('' ,port))
s.listen(1)
(conn,addr)=s.accept()
print ("Connected to " + str(addr))
#--------------------------Main loop--------------------#
cb = pi.callback(21,pigpio.RISING_EDGE, cbf)
while True:
sendData ()-

Use open(file, mode) with the pathname of a file as file and mode as "w" to open the file for writing. Call file. write(data) with data as the string formats "%s %d" followed by % and a tuple containing a string of the variable name, and the variable. Hope this works!

You can try
file = open("fileName.txt","w")
file.write(str(velocity) + "\n")
file.close()
"w" in line 1 means you are writing to the file. Adding "\n" means here is the end of the content.

How to timestamp data collected using PySerial and export to csv?

I'm trying to collect serial data from multiple devices, timestamp and export it to a .csv file. I want to write separate modules for each device such that they return the data to the main module and all the writing to csv is done in that.
The following program writes date and time to csv but not the data returned from the device module.
import time
import csv
from threading import Thread
import fio2
def Csv_creator():
my_file = open('test_csv.csv', 'w+')
with my_file:
new_file = csv.writer(my_file)
def Timestamp():
date_now = time.strftime('%d/%m/%y')
time_now = time.strftime('%H:%M:%S')
return [date_now,time_now]
def Write_loop():
Csv_creator()
fio2.Initialize()
while True:
with open('test_csv.csv', 'a') as f:
[date_now,time_now] = Timestamp()
fio2_data = fio2.Reader()
print fio2_data
to_write = [date_now,time_now,fio2_data]
csv_file = csv.writer(f)
csv_file.writerow(to_write)
t = Thread(target=Write_loop)
t.daemon = True
t.start()
raw_input("Press any key to stop \n")
The device module is as shown below. It works fine on it's own but I have a hard time making it return the value and have it written onto the csv file.
import serial
ser = serial.Serial("COM6",
baudrate=2400,
bytesize=serial.EIGHTBITS,
parity =serial.PARITY_ODD,
timeout=1,
writeTimeout =1)
def Initialize():
global ser
try:
ser.isOpen()
print("\n Serial is open")
except:
print ("Error: serial Not Open")
def Reader():
global ser
if (ser.isOpen()):
try:
x = ser.readline().decode()
x = (x)
return x
except:
return "unable to print"
else:
return "cannot open serial port"

Rather than opening the file each time in your loop, I would suggest moving it outside:
with open('test_csv.csv', 'a') as f:
csv_file = csv.writer(f)
while True:
date_now, time_now = Timestamp()
fio2_data = fio2.Reader()
csv_file.writerow([date_now, time_now, fio2_data])

I figured it out. I had to remove some garbage letters that were associated with the decimal values. First, I change the received data to string and replaced the garbage letters. Here's how I changed it:
[date_now,time_now] = Timestamp()
fio2_data = str(fio2.Reader()).replace("\r\n","")
fio2_data = fio2_data.replace("\x000","")
write_list = [date_now,time_now,fio2_data]

python exporting csv file from sqlite database the values which has capital " L" are truncated

import sqlite3
import pandas as pd
f = open('output.csv', 'w')
connection = sqlite3.connect('storage.sqlite')
cursor = connection.cursor()
cursor.execute('select * from product')
while True:
df = pd.DataFrame(cursor.fetchmany(1000))
if len(df) == 0:
break
else:
df.to_csv(f, header=False)
f.close()
cursor.close()
connection.close()
here the data was "Long Lad as" so while importing i got "ong ad as " in different cells of csv.
small "l" are not effected but capital L are being removed while exporting.
please help to fix this bug

See your image - you have set L as Other separator - so you remove L when you import file.
CSV is normal text file so you can open in normal editor and see if you have this L in text.

Unable to write list back to CSV

I am trying to write a code that takes in a csv, runs a ping on the value in the first column and then outputs the status to the second column. Everything in the code runs fine until it tries to write out to the csv at which time I get this error
line 35, in writer.writerows(columns)
TypeError: 'str' does not support the buffer interface
import os
import csv
from collections import defaultdict
i = 0
#read file
columns = defaultdict(list)
with open('hosts.csv') as f:
reader = csv.DictReader(f)
for row in reader:
for (k,v) in row.items():
columns[k].append(v)
f.close()
print('[DEBUG]', columns['host'])
print('[DEBUG] 1st host is', (columns['host'])[0])
print('[DEBUG]', columns['status'])
#ping hosts
hostname = (columns['host'])[i]
response = os.system("ping -n 1 " + hostname)
print ("[DEBUG]", response)
if response == 0:
print (hostname, 'is up')
(columns['status'])[i] = 'Up'
i = i+1
else:
print (hostname, 'is down')
(columns['status'])[i] = 'Down'
i = i+1
#write results
with open("hosts.csv", "wb") as f:
writer =csv.writer(f)
print("[DEBUG] just before write rows")
writer.writerows(columns)
print("[DEBUG] after write rows")
f.close()
The csv contains the following
host,status,name
8.8.8.8,down,google.com
and should return
host,status,name
8.8.8.8,Up,google.com
I am using Python 3.4

You are reading the CSV in one format and writing in another one, where columns is defaultdict with list of values inside a dict.
Here's a better way to solve this problem, maintaing the original file structure:
import os
import csv
with open('hosts.csv') as f:
reader = csv.DictReader(f)
rows = list(reader)
hosts = [row['host'] for row in rows]
statuses = [row['status'] for row in rows]
print('[DEBUG]', hosts)
print('[DEBUG] 1st host is', hosts[0])
print('[DEBUG]', statuses)
for row in rows:
#ping hosts
hostname = row['host']
response = os.system("ping -n 1 " + hostname)
print ("[DEBUG]", response)
if response == 0:
print (hostname, 'is up')
row['status'] = 'Up'
else:
print (hostname, 'is down')
row['status'] = 'Down'
#write results
with open("hosts.csv", "wb") as f:
writer = csv.DictWriter(f, reader.fieldnames)
# to maintain the same structure from the original file, rewrite header in original position
writer.writeheader()
print("[DEBUG] just before write rows")
writer.writerows(rows)
print("[DEBUG] after write rows")
Before instantiate csv.DictWriter, you can change the field names that you want to be in the new file:
newfieldnames = csvreader.fieldnames
lastfield = newfieldnames.pop() # remove last field
if 'field_name' in newfieldnames:
newfieldnames.remove('field_name') # remove by field name
writer = csv.DictWriter(f, newfieldnames)

get file size and append to new column of CSV file

Python 2.4
For my example I have a 2 column csv file
Eg:
HOST, FILE
server1, /path/to/file1
server2, /path/to/file2
server3, /path/to/file3
I would like to get the file size of the object at PATH for each row in the csv FILE, then add that value to the csv FILE on a new column.
Making it:
HOST, PATH, FILESIZE
server1, /path/to/file1, 6546542
server2, /path/to/file2, 46546343
server3, /path/to/file3, 87523
Ive tried a couple methods but havnt had much success.
The code below executes fileSizeCmd (du -b) on the PATH and outputs the filezie correctly, but I havnt figured out how to use the data to add to the csv FILE
import datetime
import csv
import os, time
from subprocess import Popen, PIPE, STDOUT
now = datetime.datetime.now()
fileSizeCmd = "du -b"
SP = " "
# Try to get disk size and append to another row after entry above
#st = os.stat(row[3])
#except IOError:
#print "failed to get information about", file
#else:
#print "file size:", st[ST_SIZE]
#print "file modified:", time.asctime(time.localtime(st[ST_MTIME]))
incsv = open('my_list.csv', 'rb')
try:
reader = csv.reader(incsv)
outcsv = open('results/results_' + now.strftime("%m-%d-%Y") + '.csv', 'wb')
try:
writer = csv.writer(outcsv)
for row in reader:
p = Popen(fileSizeCmd + SP + row[1], shell=True, stdin=PIPE, stdout=PIPE, stderr=PIPE)
stdout, empty = p.communicate()
print 'Command: %s\nOutput: %s\n' % (fileSizeCmd + SP + row[1], stdout)
# Results in bytes example
#
# Output:
# 8589935104 /path/to/file
#
# Write 8589935104 to new column of csv FILE
finally:
outcsv.close()
finally:
incsv.close()

Sketch w/o error handling:
#!/usr/bin/env python
import csv
import os
filename = "sample.csv"
# localhost, 01.html.bak
# localhost, 01.htmlbak
# ...
def filesize(filename):
# no need to shell out for filesize
return os.stat(filename).st_size
with open(filename, 'rb') as handle:
reader = csv.reader(handle)
# result is written to sample.csv.updated.csv
writer = csv.writer(open('%s.updated.csv' % filename, 'w'))
for row in reader:
# need to strip filename, just in case
writer.writerow(row + [ filesize(row[1].strip()) ])
# result
# localhost, 01.html.bak,10021
# localhost, 01.htmlbak,218982
# ...

You can
1) read the cvs content into a list of tuple of (server, filename)
2) collect the file size for each element of this list
3) package the result into another tuple (server, filename, filesize) into another list ('result')
4) write out the result to new file

First, getting file size is a lot easier than using subprocess (see os.stat):
>>> os.stat('/tmp/file').st_size
100
Second, you're on the right track with your writer object writing to a different file, but you just need to add a column to the row lists you're getting back from the reader and then feed them to writerow on the writer (see here). Something like this:
>>> writerfp = open('out.csv', 'w')
>>> writer = csv.writer(writerfp)
>>> for row in csv.reader(open('in.csv', 'r')):
... row.append('column')
... writer.writerow(row)
...
>>> writerfp.close()