I am trying to append to a specific line in a file by checking its first value.
deposit = str(deposit)
with open('Customer Statements.txt','r+') as a:
lines = a.readlines()
for i,line in enumerate(lines):
if line.startswith(loginDetails):
trans = ('{}/Deposit|{}'.format(dt,deposit))
with open('Customer Statements.txt','a') as a:
a.seek(0)
for line in lines:
a.write(line)
break
Please help! This is my code that i tried to make this work but in vain
are you seraching for the "a", append mode?
the code:
with open("file", "a") as f:
f.write("text")
will append the string "text" at the end of the file "file" without deleting the current content of file.
in you case you probably want something close to:
with open('Customer Statements.txt','a') as a:
a.write(deposit)
Related
I am having trouble writing the entire list into an outfile. Here is the code:
with open(infline, "r") as f:
lines = f.readlines()
for l in lines:
if "ATOM" in l :
split = l.split()
if split[-1] == "1":
print(split)
#print(type(split))
with open( newFile,"w") as f:
f.write("Model Number One" + "\n")
f.write(str(split))
When I use print(split) it allows me to see the entire list (image below):
with open(infile, "r") as f:
lines = f.readlines()
for l in lines:
if "ATOM" in l :
split = l.split()
if split[-1] == "1":
#print(split)
print(type(split))
with open( newFile,"w") as f:
f.write("Model Number One" + "\n")
for i in range(len(split)):
f.write(str(split))
However, when I try to use f.write(split) I get an error because the function can only take a str not a list. So, I used f.write(str(split)) and it worked. The only issue now is that it only writes the last item in the list, not the whole list.
The function print is slightly more permissible than the method f.write, in the sense that it can accept lists and various types of objects as input. f.write is usually called by passing pre-formatted strings, as you noticed.
I think the issue with the code is that the write routine is nested inside the code. This causes Python to erase any contents stored inside newFile, and write only the last line read (l).
The problem can be easily fixed by changing the open call to open( newFile,"a"). The flag "a" tells Python to append the new contents to the existing file newFile (without erasing information). If newFile does not exist yet, Python will automatically create it.
i have a file(A.txt) that it has a series of lines. i would like to read file(A) and create a new file(B) and add a number and a semicolon at the beginning and a space before the text of each line. at the moment i have:
with open('A.txt','r+') as f:
for index, line in enumerate(f.readlines(), start=1):
print('{:4d}: {}'.format(index, line.rstrip()))
the above code takes the file(A) and adds the number in the format i want. The problem is that i do not know how to leave file(A.txt), just read the contents of A.txt, as it is and make all changes to file(B.txt).
Any ideas, please?
Open file B in write-mode, open("B.txt", "w"), then instead of calling print, call write on the new file descriptor.
with open("A.txt", "r") as a, open("B.txt", "w") as b:
b.write(...)
Your program would look like:
with open("A.txt", "r") as a, open("B.txt", "w") as b:
index = 1
for line in a:
b.write("{:4d}: {}\n".format(index, line.rstrip()))
index += 1
I need to search for a name in a file and in the line starting with that name, I need to replace the fourth item in the list that is separated my commas. I have began trying to program this with the following code, but I have not got it to work.
with open("SampleFile.txt", "r") as f:
newline=[]
for word in f.line():
newline.append(word.replace(str(String1), str(String2)))
with open("SampleFile.txt", "w") as f:
for line in newline :
f.writelines(line)
#this piece of code replaced every occurence of String1 with String 2
f = open("SampleFile.txt", "r")
for line in f:
if line.startswith(Name):
if line.contains(String1):
newline = line.replace(str(String1), str(String2))
#this came up with a syntax error
You could give some dummy data which would help people to answer your question. I suppose you to backup your data: You can save the edited data to a new file or you can backup the old file to a backup folder before working on the data (think about using "from shutil import copyfile" and then "copyfile(src, dst)"). Otherwise by making a mistake you could easily ruin your data without being able to easily restore them.
You can't replace the string with "newline = line.replace(str(String1), str(String2))"! Think about "strong" as your search term and a line like "Armstrong,Paul,strong,44" - if you replace "strong" with "weak" you would get "Armweak,Paul,weak,44".
I hope the following code helps you:
filename = "SampleFile.txt"
filename_new = filename.replace(".", "_new.")
search_term = "Smith"
with open(filename) as src, open(filename_new, 'w') as dst:
for line in src:
if line.startswith(search_term):
items = line.split(",")
items[4-1] = items[4-1].replace("old", "new")
line = ",".join(items)
dst.write(line)
If you work with a csv-file you should have a look at the csv module.
PS My files contain the following data (the filenames are not in the files!!!):
SampleFile.txt SampleFile_new.txt
Adams,George,m,old,34 Adams,George,m,old,34
Adams,Tracy,f,old,32 Adams,Tracy,f,old,32
Smith,John,m,old,53 Smith,John,m,new,53
Man,Emily,w,old,44 Man,Emily,w,old,44
So basically i have a list in a file and i only want to print the line containing an A
Here is a small part of the list
E5341,21/09/2015,C102,440,E,0
E5342,21/09/2015,C103,290,A,290
E5343,21/09/2015,C104,730,N,0
E5344,22/09/2015,C105,180,A,180
E5345,22/09/2015,C106,815,A,400
So i only want to print the line containing A
Sorry im still new at python,
i gave a try using one "print" to print the whole line but ended up failing guess i will always suck at python
You just have to:
open file
read lines
for each line, split at ","
for each line, if the 5th part of the splitted str is equal to "A", print line
Code:
filepath = 'file.txt'
with open(filepath, 'r') as f:
lines = f.readlines()
for line in lines:
if line.split(',')[4] == "A":
print(line)
So I am completely new to Python and can't figure out what's wrong with my code.
I need to write a program that asks for the name of the existing text file and then of the other one, that doesn't necessarily need to exist. The task of the program is to take content of the first file, convert it to upper-case letters and paste to the second file. Then it should return the number of symbols used in the file(s).
The code is:
file1 = input("The name of the first text file: ")
file2 = input("The name of the second file: ")
f = open(file1)
file1content = f.read()
f.close
f2 = open(file2, "w")
file2content = f2.write(file1content.upper())
f2.close
print("There is ", len(str(file2content)), "symbols in the second file.")
I created two text files to check whether Python performs the operations correctly. Turns out the length of the file(s) is incorrect as there were 18 symbols in my file(s) and Python showed there were 2.
Could you please help me with this one?
Issues I see with your code:
close is a method, so you need to use the () operator otherwise f.close does not do what your think.
It is usually preferred in any case to use the with form of opening a file -- then it is close automatically at the end.
the write method does not return anything, so file2content = f2.write(file1content.upper()) is None
There is no reason the read the entire file contents in; just loop over each line if it is a text file.
(Not tested) but I would write your program like this:
file1 = input("The name of the first text file: ")
file2 = input("The name of the second file: ")
chars=0
with open(file1) as f, open(file2, 'w') as f2:
for line in f:
f2.write(line.upper())
chars+=len(line)
print("There are ", chars, "symbols in the second file.")
input() does not do what you expect, use raw_input() instead.