For the code below, I am supposed to write three separate try/except-blocks, which react to the three following errors, respectively:
1) File is not available
2) A line in the file contains a fewer number of elements than expected
3) The user's entry cannot be found in the dictionary as a key
Also, the second error should NOT finish the program. Incorrect lines in the text-file are supposed to be skipped, so the dictionary should have three Key-Value-Pairs.
The content of the text-file looks like this. In the end, the program is supposed to be able to print both the left word(original word) and the right word (translation):
dog Hund
cat Katze
questionmark
snow Schnee
And this is the following code:
with open(filename, "r", encoding="utf8") as dictionaryfile:
for line in dictionaryfile:
elements_from_line = line.split()
word = elements_from_line[0]
translation = elements_from_line[1]
translationdictionary[word] = translation
inputword = input("Welches Wort soll übersetzt werden? >")
correct_translation = translationdictionary[inputword]
print("Das Eingabewort:\t{}\nDie Übersetzung:\t{}".format(inputword, correct_translation))
If u have to do it all in try-except blocks, it could look like this:
if the file does not exist - catch OSError
if a line contains in the file fewer elements than expected - catch IndexError
if user input is not in dictionary - it means that we have to catch KeyError
So, after that we can try something like this:
Editing your code:
filename = 'ala.txt'
translationdictionary = {}
try:
with open(filename, "r", encoding="utf8") as dictionaryfile:
for line in dictionaryfile:
elements_from_line = line.split()
try:
word = elements_from_line[0]
translation = elements_from_line[1]
translationdictionary[word] = translation
except IndexError:
continue # skip line
except OSError: # can not find file
print('File not found')
inputword = input("Welches Wort soll übersetzt werden? >")
try:
correct_translation = translationdictionary[inputword]
print("Das Eingabewort:\t{}\nDie Übersetzung:\t{}".format(inputword, correct_translation))
except KeyError: # lack of key in dict
print('Can not find input in dict')
Related
Input
02000|42163,54|
03100|4|6070,00
03110|||6070,00|00|00|
00000|31751150201912001|01072000600074639|
02000|288465,76|
03100|11|9060,00
03110|||1299,00|00|
03110||||7761,00|00|
03100|29|14031,21
03110|||14031,21|00|
00000|31757328201912001|01072000601021393|
Code
prev = ''
with open('out.txt') as f:
for line in f:
if prev.startswith('03110') and line.startswith('03110'):
print(prev.strip()+ '|03100|XX|PARCELA|' + line)
prev = line
Hi, I have this code that search if two consecutives lines startswith 03110 and print those line, but I wanna transforme the code so it prints or write at .txt also the rest of the lines
Output should be like this
02000|42163,54|
03100|4|6070,00
03110|||6070,00|00|00|
00000|31751150201912001|01072000600074639|
02000|288465,76|
03100|11|9060,00
03110|||1299,00|00|3100|XX|PARCELA|03110||||7761,00|00|
03100|29|14031,21
03110|||14031,21|00|
00000|31757328201912001|01072000601021393|
I´m know that I´m getting only those two lines merged, because that is the command at print()
03110|||1299,00|00|3100|XX|PARCELA|03110||||7761,00|00|
But I don´t know to make the desire output, can anyone help me with my code?
# I assume the input is in a text file:
with open('myFile.txt', 'r') as my_file:
splited_line = [line.rstrip().split('|') for line in my_file] # this will split every line as a separate list
new_list = []
for i in range(len(splited_line)):
try:
if splited_line[i][0] == '03110' and splited_line[i-1][0] == '03110': # if the current line and the previous line start with 03110
first = '|'.join(splited_line[i-1])
second = '|'.join(splited_line[i])
newLine = first + "|03100|XX|PARCELA|"+ second
new_list.append(newLine)
elif splited_line[i][0] == '03110' and splited_line[i+1][0] == '03110': # to escape duplicating in the list
pass
else:
line = '|'.join(splited_line[i])
new_list.append(line)
except IndexError:
pass
# To write the new_list to text files
with open('new_file' , 'a') as f:
for item in new_list:
print(item)
f.write(item + '\n')
So I have a text file, and I need to define a function to open the file, read through it, and then return and print the number of characters within the file.
So far I've got:
def num_chars_in_file(file):
path = 'planets.txt'
file_handle = open(path)
for text in file_handle:
file = file_handle.readlines()
print(file)
print(f"\nProblem 1: {num_chars_in_file()}")
# I'm not sure where to go from where.
You could create a count variable to store the cumulative total of characters as you iterate over each line, something like this:
def num_chars_in_file():
path = 'planets.txt'
file_handle = open(path)
count = 0
for text in file_handle:
count += len(text.rstrip())
file_handle.close() # Make sure to close the file if you're not using with
return count
print(f"\nProblem 1: {num_chars_in_file()}")
with open('my_words.txt') as infile:
lines=0
words=0
characters=0
for line in infile:
wordslist=line.split()
lines=lines+1
words=words+len(wordslist)
characters += sum(len(word) for word in wordslist)
print(lines)
print(words)
print(characters)
Try this to print number of line, words and characters in the file.
Refer to this similar question more details.
I'm trying to read a csv file, and create a 2 dimensional list from the values stored inside.
However I'm running into trouble when I try to check whether or not the values stored can be converted into floats.
Here is the function I have written, which reads the file and creates a list.
def readfile(amount, name):
tempfile = open(name).readlines()[1:] #First value in line is never a float, hence the [1:]
rain_list = []
count = 0.0
for line in tempfile:
line = line.rstrip()
part = line.split(",")
try:
part = float(part)
except ValueError:
print("ERROR: invalid float in line: {}".format(line))
rain_list.append(part[amount])
count += 1
if count == 0:
print("ERROR in reading the file.")
tempfile.close()
return rain_list
It might be a little messy, since it's essentially a patchwork of different possible solutions I have tried.
The values it gets are the name of the file (name) and the amount of values it reads from the file (amount).
Has anyone got an idea why this does not work as I expect it to work?
part is a list of strings. To check & convert for all floats, you'd have to do:
part = [float(x) for x in part]
(wrapped in your exception block)
BTW you should use the csv module to read comma-separated files. It's built-in. Also using enumerate would allow to be able to print the line where the error occurs, not only the data:
reader = csv.reader(tempfile) # better: pass directly the file handle
# and use next(reader) to discard the title line
for lineno,line in enumerate(reader,2): # lineno starts at 2 because of title line
try:
line = [float(x) for x in line]
except ValueError:
print("ERROR: invalid float in line {}: {}".format(lineno,line))
I am trying to pull a string of input names that get saved to a text file. I need to pull them by capital letter which is input. I.E. the saved text file contains names DanielDanClark, and I need to pull the names that begin with D. I am stuck at this part
for i in range(num):
print("Name",i+1," >> Enter the name:")
n=input("")
names+=n
file=open("names.txt","w")
file.write(names)
lookUp=input("Did you want to look up any names?(Y/N)")
x= ord(lookUp)
if x == 110 or x == 78:
quit()
else:
letter=input("Enter the first letter of the names you want to look up in uppercase:")
file=open("names.txt","r")
fileNames=[]
file.list()
for letter in file:
fileNames.index(letter)
fileNames.close()
I know that the last 4 lines are probably way wrong. It is what I tried in my last failed attempt
Lets break down your code block by block
num = 5
names = ""
for i in range(num)
print("Name",i+1," >> Enter the name:")
n=input("")
names+=n
I took the liberty of giving num a value of 5, and names a value of "", just so the code will run. This block has no problems. And will create a string called names with all the input taken. You might consider putting a delimiter in, which makes it more easier to read back your data. A suggestion would be to use \n which is a line break, so when you get to writing the file, you actually have one name on each line, example:
num = 5
names = ""
for i in range(num)
print("Name",i+1," >> Enter the name:")
n = input()
names += n + "\n"
Now you are going to write the file:
file=open("names.txt","w")
file.write(names)
In this block you forget to close the file, and a better way is to fully specify the pathname of the file, example:
file = open(r"c:\somedir\somesubdir\names.txt","w")
file.write(names)
file.close()
or even better using with:
with open(r"c:\somedir\somesubdir\names.txt","w") as openfile:
openfile.write(names)
The following block you are asking if the user want to lookup a name, and then exit:
lookUp=input("Did you want to look up any names?(Y/N)")
x= ord(lookUp)
if x == 110 or x == 78:
quit()
First thing is that you are using quit() which should not be used in production code, see answers here you really should use sys.exit() which means you need to import the sys module. You then proceed to get the numeric value of the answer being either N or n and you check this in a if statement. You do not have to do ord() you can use a string comparisson directly in your if statement. Example:
lookup = input("Did you want to look up any names?(Y/N)")
if lookup.lower() == "n":
sys.exit()
Then you proceed to lookup the requested data, in the else: block of previous if statement:
else:
letter=input("Enter the first letter of the names you want to look up in uppercase:")
file=open("names.txt","r")
fileNames=[]
file.list()
for letter in file:
fileNames.index(letter)
fileNames.close()
This is not really working properly either, so this is where the delimiter \n is coming in handy. When a text file is opened, you can use a for line in file block to enumerate through the file line by line, and with \n delimiter added in your first block, each line is a name. You also go wrong in the for letter in file block, it does not do what you think it should be doing. It actually returns each letter in the file, regardless of whay you type in the input earlier. Here is a working example:
letter = input("Enter the first letter of the names you want to look up in uppercase:")
result = []
with open(r"c:\somedir\somesubdir\names.txt", "r") as openfile:
for line in openfile: ## loop thru the file line by line
line = line.strip('\n') ## get rid of the delimiter
if line[0].lower() == letter.lower(): ## compare the first (zero) character of the line
result.append(line) ## append to result
print(result) ## do something with the result
Putting it all together:
import sys
num = 5
names = ""
for i in range(num)
print("Name",i+1," >> Enter the name:")
n = input("")
names += n + "\n"
with open(r"c:\somedir\somesubdir\names.txt","w") as openfile:
openfile.write(names)
lookup = input("Did you want to look up any names?(Y/N)")
if lookup.lower() == "n":
sys.exit()
letter = input("Enter the first letter of the names you want to look up in uppercase:")
result = []
with open(r"c:\somedir\somesubdir\names.txt", "r") as openfile:
for line in openfile:
line = line.strip('\n')
if line[0].lower() == letter.lower():
result.append(line)
print(result)
One caveat I like to point out, when you create the file, you open the file in w mode, which will create a new file every time, therefore overwriting the a previous file. If you like to append to a file, you need to open it in a mode, which will append to an existing file, or create a new file when the file does not exist.
I've been learning Python and I wanted to write a script to count the number of characters in a text and calculate their relative frequencies. But first, I wanted to know the length of the file. My intention is that, while the script goes from line to line counting all the characters, it would print the current line and the total number of lines, so I could know how much it is going to take.
I executed a simple for loop to count the number of lines, and then another for loop to count the characters and put them in a dictionary. However, when I run the script with the first for loop, it stops early. It doesn't even go into the second for loop as far as I know. If I remove this loop, the rest of the code goes on fine. What is causing this?
Excuse my code. It's rudimentary, but I'm proud of it.
My code:
import string
fname = input ('Enter a file name: ')
try:
fhand = open(fname)
except:
print ('Cannot open file.')
quit()
#Problematic bit. If this part is present, the script ends abruptly.
#filelength = 0
#for lines in fhand:
# filelength = filelength + 1
counts = dict()
currentline = 1
for line in fhand:
if len(line) == 0: continue
line = line.translate(str.maketrans('','',string.punctuation))
line = line.translate(str.maketrans('','',string.digits))
line = line.translate(str.maketrans('','',string.whitespace))
line = line.translate(str.maketrans('','',""" '"’‘“” """))
line = line.lower()
index = 0
while index < len(line):
if line[index] not in counts:
counts[line[index]] = 1
else:
counts[line[index]] += 1
index += 1
print('Currently at line: ', currentline, 'of', filelength)
currentline += 1
listtosort = list()
totalcount = 0
for (char, number) in list(counts.items()):
listtosort.append((number,char))
totalcount = totalcount + number
listtosort.sort(reverse=True)
for (number, char) in listtosort:
frequency = number/totalcount*100
print ('Character: %s, count: %d, Frequency: %g' % (char, number, frequency))
It looks fine the way you are doing it, however to simulate your problem, I downloaded and saved a Guttenberg text book. It's a unicode issue. Two ways to resolve it. Open it as a binary file or add the encoding. As it's text, I'd go the utf-8 option.
I'd also suggest you code it differently, below is the basic structure that closes the file after opening it.
filename = "GutenbergBook.txt"
try:
#fhand = open(filename, 'rb')
#open read only and utf-8 encoding
fhand = open(filename, 'r', encoding = 'utf-8')
except IOError:
print("couldn't find the file")
else:
try:
for line in fhand:
#put your code here
print(line)
except:
print("Error reading the file")
finally:
fhand.close()
For the op, this is a specific occasion. However, for visitors, if your code below the for state does not execute, it is not a python built-in issue, most likely to be: an exception error handling in parent caller.
Your iteration is inside a function, which is called inside a try except block of caller, then if any error occur during the loop, it will get escaped.
This issue can be hard to find, especially when you dealing with intricate architecture.