I'm trying to make a code that would take the information a user inputs and adds it permanently to a different file's variable:
main.py:
text = "hello world"
f = open("Testfile.py", "a+")
f.write(text)
Testfile.py:
w = ["bob", "joe", "emily"]Hello World
how can I make it so that "Hello World" would appear in w such as
w = ["bob", "joe", "emily", "Hello World"]
Edit:
what if w is a library such as
w = {"bob": 0, "joe": 0, "emily" : 0}
and I want to add "Hello World" : 0 to it
Is it really necessary to store the content of you array to a python file?
You could store it into a yaml file for instance instead, and you a yaml library to write and read the content to/from that file.
import yaml
import os
def load_yaml(filename):
with open(filename, 'r') as fp:
y = yaml.safe_load(fp)
return y
def save_yaml(content, filename):
if os.path.exists(filename):
os.remove(filename)
with open(filename, 'w') as fp:
yaml.safe_dump(content, fp, default_flow_style=False)
w = ["bob", "joe", "emily"]
save_yaml(w, "data.yaml")
w.append("hello world")
save_yaml(w, "data.yaml")
content = load_yaml("data.yaml")
print(content)
I would strongly recommend not modifying a python file programmatically. You will likely be able to accomplish the same task by storing your list in a text file and having any program read the text file and build the list. There are other file formats you could use for more complicated tasks, but for simply putting strings in a list this code is sufficient. Some kind of full-on database would be best for a real-world application.
test.txt:
bob
joe
emily
main.py:
def read_file():
f = open('test.txt', 'r')
lines = f.readlines()
lines = [line.strip() for line in lines] #removes the '\n' character at the end of each line
print(lines)
f.close()
def append_file(item):
f = open('test.txt', 'a')
f.write(item)
f.write('\n')
f.close()
read_file()
append_file("Hello World")
append_file("test")
read_file()
Also as a bonus, you can use with to manage file objects more concisely.
def read_file():
with open('test.txt', 'r') as f:
lines = f.readlines()
lines = [line.strip() for line in lines] #removes the '\n' character at the end of each line
print(lines)
def append_file(item):
with open('test.txt', 'a') as f:
f.write(item)
f.write('\n')
Related
I have many text files, and each of them has a empty line at the end. My scripts did not seem to remove them. Can anyone help please?
# python 2.7
import os
import sys
import re
filedir = 'F:/WF/'
dir = os.listdir(filedir)
for filename in dir:
if 'ABC' in filename:
filepath = os.path.join(filedir,filename)
all_file = open(filepath,'r')
lines = all_file.readlines()
output = 'F:/WF/new/' + filename
# Read in each row and parse out components
for line in lines:
# Weed out blank lines
line = filter(lambda x: not x.isspace(), lines)
# Write to the new directory
f = open(output,'w')
f.writelines(line)
f.close()
You can use Python's rstrip() function to do this as follows:
filename = "test.txt"
with open(filename) as f_input:
data = f_input.read().rstrip('\n')
with open(filename, 'w') as f_output:
f_output.write(data)
This will remove all empty lines from the end of the file. It will not change the file if there are no empty lines.
you can remove last empty line by using:
with open(filepath, 'r') as f:
data = f.read()
with open(output, 'w') as w:
w.write(data[:-1])
You can try this without using the re module:
filedir = 'F:/WF/'
dir = os.listdir(filedir)
for filename in dir:
if 'ABC' in filename:
filepath = os.path.join(filedir,filename)
f = open(filepath).readlines()
new_file = open(filepath, 'w')
new_file.write('')
for i in f[:-1]:
new_file.write(i)
new_file.close()
For each filepath, the code opens the file, reads in its contents line by line, then writes over the file, and lastly writes the contents of f to the file, except for the last element in f, which is the empty line.
You can remove the last blank line by the following command. This worked for me:
file = open(file_path_src,'r')
lines = file.read()
with open(file_path_dst,'w') as f:
for indx, line in enumerate(lines):
f.write(line)
if indx != len(lines) - 1:
f.write('\n')
i think this should work fine
new_file.write(f[:-1])
I'm a bit new to Python and I am trying to simplify my existing code.
Right now, I have the code repeated 5 times with different strings. I'd like to have the code one time and have it run through a list of strings.
Currently what I have:
def wiScanFormat():
File = open("/home/pi/gpsMaster/WiScan.txt", "r")
data = File.read()
File.close()
MAC = data.replace("Address:", "\nAddress, ")
File = open("/home/pi/gpsMaster/WiScan.txt", "w")
File.write(MAC)
File.close()
File = open("/home/pi/gpsMaster/WiScan.txt", "r")
data = File.read()
File.close()
SSID = data.replace("ESSID:", "\nESSID, ")
File = open("/home/pi/gpsMaster/WiScan.txt", "w")
File.write(SSID)
File.close()
File = open("/home/pi/gpsMaster/WiScan.txt", "r")
data = File.read()
File.close()
FREQ = data.replace("Frequency:", "\nFrequency, ")
File = open("/home/pi/gpsMaster/WiScan.txt", "w")
File.write(FREQ)
File.close()
File = open("/home/pi/gpsMaster/WiScan.txt", "r")
data = File.read()
File.close()
QUAL = data.replace("Quality", "\nQuality, ")
File = open("/home/pi/gpsMaster/WiScan.txt", "w")
File.write(QUAL)
File.close()
File = open("/home/pi/gpsMaster/WiScan.txt", "r")
data = File.read()
File.close()
SIG = data.replace("Signal level", "\nSignal Level, ")
File = open("/home/pi/gpsMaster/WiScan.txt", "w")
File.write(SIG)
File.close()
What I'd like to have:
ORG = ['Address:', 'ESSID:'...etc]
NEW = ['\nAddress, ' , '\nESSID, ' , ... etc]
and run that through:
File = open("/home/pi/gpsMaster/WiScan.txt", "r")
data = File.read()
File.close()
ID = data.replace("ORG", "NEW")
File = open("/home/pi/gpsMaster/WiScan.txt", "w")
File.write(ID)
File.close()
I've tried running exactly what I put up, but it does not seem to format it the way I need to.
The output from above looks like:
Cell 46 - Address: xx:xx:xx:xx:xx:xx ESSID:"MySSID" Frequency:2.412 GHz (Channel 1) Quality=47/100 Signal level=48/100 Quality=47/100 Signal level=48/100
But it is supposed to look like this (And it does when I run that same block over the strings separately):
xx:xx:xx:xx:xx:xx MySSID 5.18 GHz (Channel 36) 0.81 0.99
How should I go about looping this block of code through my list of strings?
There two strings that I would need for the find and replace, old and new, so they would have to work together. These lists will be the same size, obviously, and I need them to be in the correct order. Address with address, ESSID with ESSID, etc.
Thanks in advance!
Try something like this:
ORG = ['Address:', 'ESSID:'...etc]
NEW = ['\nAddress, ' , '\nESSID, ' , ... etc]
File = open("/home/pi/gpsMaster/WiScan.txt", "r")
data = File.read()
File.close()
for org, new in zip(ORG, NEW):
data = data.replace(org, new)
File = open("/home/pi/gpsMaster/WiScan.txt", "w")
File.write(data)
File.close()
(Note the way zip works: https://docs.python.org/2/library/functions.html#zip)
If I am reading your question right, you are opening the same file, making a small alteration, saving it, and then closing it again, five times. You could just open it once, make all the alterations, and then save it. For instance, like this:
filename = "/home/pi/gpsMaster/WiScan.txt"
with open(filename, 'r') as fin:
data = fin.read()
data = data.replace("Address:", "\nAddress, ")
data = data.replace("ESSID:", "\nESSID, ")
data = data.replace("Frequency:", "\nFrequency, ")
data = data.replace("Quality", "\nQuality, ")
data = data.replace("Signal level", "\nSignal Level, ")
with open(filename, 'w') as fout:
fout.write(data)
If you want to use lists (ORG and NEW) for your replacements, you could do this:
with open(filename, 'r') as fin:
data = fin.read()
for o,n in zip(ORG, NEW):
data = data.replace(o,n)
with open(filename, 'w') as fout:
fout.write(data)
Given your ORG and NEW, the simplest way to do this would be something like:
# Open once for both read and write; use with statement for guaranteed close at end of block
with open("/home/pi/gpsMaster/WiScan.txt", "r+") as f:
data = f.read() # Slurp file
f.seek(0) # Seek back to beginning of file
# Perform all replacements
for orig, repl in zip(ORG, NEW):
data = data.replace(orig, repl)
f.write(data) # Write new data over old
f.truncate() # If replacement shrunk file, truncate extra
You could just do this:
def wiScanFormat(path = "/home/pi/gpsMaster/WiScan.txt"):
# List of tuples with strings to find and strings to replace with
replacestr = [
("Address:", "\nAddress, "),
("ESSID:", "\nESSID, "),
("Frequency:", "\nFrequency, "),
("Quality", "\nQuality, "),
("Signal level", "\nSignal Level, ")
]
with open(path, "r") as file: # Open a file
data = file.read()
formated = data
for i in replacestr: # Loop over each element (tuple) in the list
formated = formated.replace(i[0], i[1]) # Replace the data
with open(path, "w") as file:
written = file.write(formated) # Write the data
return written
I've seen really complex answers on this website as how to edit a specific line on a file but I was wondering if there was a simple way to do it?
I want to search for a name in a file, and on the line that I find that name on, I want to add an integer to the end of the line (as it is a score for a quiz). Or could you tell me how I can replace the entirety of the line with new data?
I have tried a lot of coding but either no change is made, or all of the data in the file gets deleted.
I tried this....
with open ('File.py', 'r') as class_file:
for number, line in enumerate(class_file):
if name in line:
s=open('File.py', 'r').readlines()
s[number]=str(data)
class_file=open('File.py', 'w')
class_file.writelines(new_score)
class_file.close()
As well as this function....
def replace (file, line_number, add_score):
s=open(file, 'w')
new_data=line[line_number].replace(line, add_score)
s.write(str(new_data))
s.close()
As well as this...
def replace_score(file_name, line_num, text):
new = open(file_name, 'r').readlines()
new[line_num] = text
adding_score= open(file_name, 'w')
adding_score.writelines(new)
adding_score.close()
But I still can't get it to work.
The last code works if I'm trying to replace the first line, but not the others.
You need to get the content of the file. Close the file. Modify the content and rewrite the file with the modified content. Try the following:
def replace_score(file_name, line_num, text):
f = open(file_name, 'r')
contents = f.readlines()
f.close()
contents[line_num] = text+"\n"
f = open(file_name, "w")
contents = "".join(contents)
f.write(contents)
f.close()
replace_score("file_path", 10, "replacing_text")
This is Tim Osadchiy's code:
def replace_score(file_name, line_num, text):
f = open(file_name, 'r')
contents = f.readlines()
f.close()
contents[line_num] = text+"\n"
f = open(file_name, "w")
contents = "".join(contents)
f.write(contents)
f.close()
replace_score("file_path", 10, "replacing_text")
This code does work but just remember that the line_num will always be one above the actual line number (as it is an index). So if you wanted line 9 then enter 8, not 9. Also, do not forget to put .txt at the end of the file path (I would've commented but do not have a high enough reputation)
The problem I am having at this point in time (being new to Python) is writing strings to a text file. The issue I'm experiencing is one where either the strings don't have linebreaks inbetween them or there is a linebreak after every character. Code to follow:
import string, io
FileName = input("Arb file name (.txt): ")
MyFile = open(FileName, 'r')
TempFile = open('TempFile.txt', 'w', encoding='UTF-8')
for m_line in MyFile:
m_line = m_line.strip()
m_line = m_line.split(": ", 1)
if len(m_line) > 1:
del m_line[0]
#print(m_line)
MyString = str(m_line)
MyString = MyString.strip("'[]")
TempFile.write(MyString)
MyFile.close()
TempFile.close()
My input looks like this:
1 Jargon
2 Python
3 Yada Yada
4 Stuck
My output when I do this is:
JargonPythonYada YadaStuck
I then modify the source code to this:
import string, io
FileName = input("Arb File Name (.txt): ")
MyFile = open(FileName, 'r')
TempFile = open('TempFile.txt', 'w', encoding='UTF-8')
for m_line in MyFile:
m_line = m_line.strip()
m_line = m_line.split(": ", 1)
if len(m_line) > 1:
del m_line[0]
#print(m_line)
MyString = str(m_line)
MyString = MyString.strip("'[]")
#print(MyString)
TempFile.write('\n'.join(MyString))
MyFile.close()
TempFile.close()
Same input and my output looks like this:
J
a
r
g
o
nP
y
t
h
o
nY
a
d
a
Y
a
d
aS
t
u
c
k
Ideally, I would like each of the words to appear on a seperate line without the numbers in front of them.
Thanks,
MarleyH
You have to write the '\n' after each line, since you're stripping the original '\n';
Your idea of using '\n'.join() doesn't work because it will use\n to join the string, inserting it between each char of the string. You need a single \n after each name, instead.
import string, io
FileName = input("Arb file name (.txt): ")
with open(FileName, 'r') as MyFile:
with open('TempFile.txt', 'w', encoding='UTF-8') as TempFile:
for line in MyFile:
line = line.strip().split(": ", 1)
TempFile.write(line[1] + '\n')
fileName = input("Arb file name (.txt): ")
tempName = 'TempFile.txt'
with open(fileName) as inf, open(tempName, 'w', encoding='UTF-8') as outf:
for line in inf:
line = line.strip().split(": ", 1)[-1]
#print(line)
outf.write(line + '\n')
Problems:
the result of str.split() is a list (this is why, when you cast it to str, you get ['my item']).
write does not add a newline; if you want one, you have to add it explicitly.
Currently I'm using this:
f = open(filename, 'r+')
text = f.read()
text = re.sub('foobar', 'bar', text)
f.seek(0)
f.write(text)
f.close()
But the problem is that the old file is larger than the new file. So I end up with a new file that has a part of the old file on the end of it.
If you don't want to close and reopen the file, to avoid race conditions, you could truncate it:
f = open(filename, 'r+')
text = f.read()
text = re.sub('foobar', 'bar', text)
f.seek(0)
f.write(text)
f.truncate()
f.close()
The functionality will likely also be cleaner and safer using open as a context manager, which will close the file handler, even if an error occurs!
with open(filename, 'r+') as f:
text = f.read()
text = re.sub('foobar', 'bar', text)
f.seek(0)
f.write(text)
f.truncate()
The fileinput module has an inplace mode for writing changes to the file you are processing without using temporary files etc. The module nicely encapsulates the common operation of looping over the lines in a list of files, via an object which transparently keeps track of the file name, line number etc if you should want to inspect them inside the loop.
from fileinput import FileInput
for line in FileInput("file", inplace=1):
line = line.replace("foobar", "bar")
print(line)
Probably it would be easier and neater to close the file after text = re.sub('foobar', 'bar', text), re-open it for writing (thus clearing old contents), and write your updated text to it.
I find it easier to remember to just read it and then write it.
For example:
with open('file') as f:
data = f.read()
with open('file', 'w') as f:
f.write('hello')
To anyone who wants to read and overwrite by line, refer to this answer.
https://stackoverflow.com/a/71285415/11442980
filename = input("Enter filename: ")
with open(filename, 'r+') as file:
lines = file.readlines()
file.seek(0)
for line in lines:
value = int(line)
file.write(str(value + 1))
file.truncate()
Honestly you can take a look at this class that I built which does basic file operations. The write method overwrites and append keeps old data.
class IO:
def read(self, filename):
toRead = open(filename, "rb")
out = toRead.read()
toRead.close()
return out
def write(self, filename, data):
toWrite = open(filename, "wb")
out = toWrite.write(data)
toWrite.close()
def append(self, filename, data):
append = self.read(filename)
self.write(filename, append+data)
Try writing it in a new file..
f = open(filename, 'r+')
f2= open(filename2,'a+')
text = f.read()
text = re.sub('foobar', 'bar', text)
f.seek(0)
f.close()
f2.write(text)
fw.close()