I'm fairly new to coding and am having some issues printing a text file.
Here's my file:
Player1: 1
Player2: 3
Here's my code:
try:
scoreTable = open("scoreTable.txt", "r")
line = scoreTable.readlines()
for i in range(0, (len(line))):
print(scoreTable.read(len(line[i].strip("\n"))))
scoreTable.close()
except FileNotFoundError:
pass
At the moment its just printing whitespace.
I'm probably missing something obvious or have gone down the wrong road altogether, so any help would be appreciated.
Thanks in advance.
Just use the below code sample to print the whole file.
try:
with open("scoreTable.txt", "r" ) as scoreTable:
file_content = scoreTable.read()
print str(file_content)
except FileNotFoundError as e:
print e.message
You are performing read operation on scoreTable.txt twice, which is not required.
try:
scoreTable = open("scoreTable.txt", "r")
lines = scoreTable.readlines()
#here in lines you have whole file stored so no need to try to read from files variable again
for line in lines:
print line
scoreTable.close()
except FileNotFoundError:
pass
While we are on this subject use with statement to read files(so you wont have to keep track to close the file)
with open("scoreTable.txt", "r" ) as f:
lines = f.readlines()
for line in lines:
print line
Related
When I run this code, a NameError traceback error pops up, even though it should be handled by the exception. Why is that?
The function call argument is intentionally misspelled.
filename_cats = "cats.txt"
filename_dogs = "dogs.txt"
def readlines(filename):
"""read lines from a text file"""
try:
with open(filename) as f:
lines = f.readlines()
string = ''
for line in lines:
string += line
except (NameError, FileNotFoundError):
print(f"The file {filename} was not found.")
else:
print(string)
readlines(filename_cat)
It's because the error happens here:
👇
readlines(filename_cat) 👈
☝️
Not anywhere in here:
try:
with open(filename) as f:
lines = f.readlines()
string = ''
for line in lines:
string += line
except (NameError, FileNotFoundError):
A try..except block can only catch errors happening literally within it, not anything happening before or after it.
I am going through Intro to Programming so basic stuff here, I have an assignment to "write a program that asks a user for a file name and then displays the first 5 lines of the file," I just can't figure out how to use the input command in this situation and then transfer to open()
Edit: Sorry here is a code snippet I had, I just don't get how to apply input from here.
def main():
#This function writes to the testFile.docx file
outfile = open('testFile.docx', 'w')
outfile.write('Hello World\n')
outfile.write('It is raining outside\n')
outfile.write('Ashley is sick\n')
outfile.write('My dogs name is Bailey\n')
outfile.write('My cats name is Remi\n')
outfile.write('Spam Eggs and Spam\n')
outfile.close()
infile = open('testFile.docx', 'r')
testFileContent = infile.read()
infile.close()
print(testFileContent)
main()
First, we ask for a filename. Then we use the try clause, which checks whether the file exists. If it does it will print 5 lines. If it does not, it will print No such a file found!
x = input('Enter a file name')
try:
with open(x) as f:
data = f.readlines()
for i in range(5):
print(data[i])
except:
print('No such a file found!')
Using a simple function,
def hello_user():
user_input = input('Enter file name: ')
try:
with open(user_input, 'r') as f:
data = f.readlines()
data = data[:5]
for o in data:
print(o.strip())
except FileNotFoundError:
print('Not found ')
hello_user()
It asks for a file name
If the file exists in the same directory the script is running, it opens the file and read each lines (white lines inclusive)
We select only the first 5 lines
We iterate through the list and remove the extra whitespace character(e.g \n).
If the file was not found, we catch the exception.
input() is used to receive input from the user. Once we recieve the input, we use the open() method to read the file in read mode.
def main():
file = input("Please enter a file name")
with open(file, 'r') as f:
lines = f.readlines()
print(lines[:5])
The with statement makes sure that it closes the file automatically without explicitly calling f.close()
The method f.readlines() returns an array containing the lines in the file.
The print() statement prints the first 5 lines of the file.
So guys, i'm tryng to make a password generator but i'm having this trouble:
First, the code i use for tests:
idTest= "TEST"
passwrd= str(random.randint(11, 99))
if not os.path.exists('Senhas.txt'):
txtFileW = open('Senhas.txt', 'w')
txtFileW.writelines(f'{idTest}: {passwrd}\n')
txtFileW.close()
else:
txtFileA = open('Senhas.txt', 'a')
txtFileA.write(f'{idTest}: {passwrd}\n')
txtFileA.close()
print(f'{idTest}: {passwrd}')
Well, what i'm expecting is something like this:
else:
with open('Senhas.txt', 'r+') as opened:
opened.read()
for lines in opened:
if something == idTest:
lines.replace(f'{something}', f'{idTest}')
else:
break
txtFileA = open('Senhas.txt', 'a')
txtFileA.write(f'{idTest}: {passwrd}\n')
txtFileA.close()
print(f'{idTest}: {passwrd}')
I've searched for it but all i've found are ways to separate it in 2 files (for my project it doesn't match) or with "static" strings, that doesn't match for me as well.
You can use the fileinput module to update the file in place.
import fileinput
with fileinput.input(files=('Senhas.txt'), inplace=True) as f:
for line in f:
if (line.startswith(idTest+':'):
print(f'{idTest}: {passwrd}')
else:
print(line)
I have been following the 'Python for dummies' book and there is one example that doesn't print out the result as I expected.
class Error(Exception):
pass
class NotEnoughStuffError(Error):
pass
try:
thefile = open('people.csv')
line_count = len(thefile.readlines())
if line_count < 2:
raise NotEnoughStuffError
except NotEnoughStuffError:
print('Not Enough Stuff')
except FileNotFoundError:
print('File not found')
thefile.close()
else:
for line in thefile:
print(line)
thefile.close()
print('Success!')
Question 1: When it prints, it should show all the lines from thefile. However, it only prints 'Success!' Why the content from thefile was not printed?
Question 2: I replaced the code:
class Error(Exception):
pass
class NotEnoughStuffError(Error):
pass
with
class NotEnoughStuffError(Exception):
pass
Do they return the same result? Is 'Exception' a built-in class in Python?
Problem is because you used readlines() and it moved pointer to the end of file and when you later use for line in thefile: then it tries to read from end of file. And it reads nothing from the end of file and it display nothing.
You would have assing list with lines to variable
all_lines = thefile.readlines()
line_count = len(all_lines)
and later use this list
for line in all_lines:
print(line)
Or you would have to move pointer to the beginning of file before you try to read again data
thefile.seek(0)
for line in thefile:
print(line)
I want this to recursively call the next file, listed in a manually inputted file. It is the first word listed in the file.
The current error messege is:
OSError: [Errno 22] Invalid argument: 'file1.txt\n'.
This is my current code:
import os
def crawl(fname):
infile = open(fname, 'r')
if os.stat(fname)[6]==0:
return "Visiting {}".format(fname)
infile.close()
else:
print ("Visiting {}".format(fname))
lines = infile.read().splitlines()
nextfile = lines[0].strip()
for line in lines:
crawl(nextfile)
Try:
import os
def crawl(fname):
with open(fname, "r") as infile:
print("Visiting {}".format(fname))
if os.stat(fname).st_size:
lines = infile.read().splitlines()
for line in lines:
crawl(line)
I'm pretty sure the problem is that you're getting a newline at the end of the filename you are reading from the first file. You can easily fix it, by using the strip method to remove the newline:
nextfile = lines[0].strip()