How to read one character from a file as a key into a dictionary, then make the next n characters its value?
Lets say we have a .txt file like so (all on one line):
A2.)43@|@C3::#
So we want "A" as key for the value ".)" and "4" as key for the value "@|@" etc.. The number after the key tells us how many characters to read as the value, and the character after is the key for the next item in the dictionary.
The thing I'm struggling with is writing the loop. I'm thinking that we might want to iterate over the length of the file using a for loop. But I don't really know how to proceed.
python file dictionary file-read
edited Nov 12 '18 at 23:18
martineau
65.9k989177
asked Nov 12 '18 at 22:28
bullebullebagarn
162
add a comment |
Lets say we have a .txt file like so (all on one line):
A2.)43@|@C3::#
So we want "A" as key for the value ".)" and "4" as key for the value "@|@" etc.. The number after the key tells us how many characters to read as the value, and the character after is the key for the next item in the dictionary.
The thing I'm struggling with is writing the loop. I'm thinking that we might want to iterate over the length of the file using a for loop. But I don't really know how to proceed.
python file dictionary file-read
edited Nov 12 '18 at 23:18
martineau
65.9k989177
asked Nov 12 '18 at 22:28
bullebullebagarn
162
1
Awhileloop would be better so you can increment the index variable arbitrarily (or check for end of file instead) to process all characters of a value at once.
– Michael Butscher
Nov 12 '18 at 22:31
Here's a hint: go to class and read your notes.
– Julien
Nov 12 '18 at 22:34
Why would the "3" character following the "4" be skipped?
– martineau
Nov 12 '18 at 23:21
add a comment |
Lets say we have a .txt file like so (all on one line):
A2.)43@|@C3::#
So we want "A" as key for the value ".)" and "4" as key for the value "@|@" etc.. The number after the key tells us how many characters to read as the value, and the character after is the key for the next item in the dictionary.
The thing I'm struggling with is writing the loop. I'm thinking that we might want to iterate over the length of the file using a for loop. But I don't really know how to proceed.
python file dictionary file-read
edited Nov 12 '18 at 23:18
martineau
65.9k989177
asked Nov 12 '18 at 22:28
bullebullebagarn
162
Lets say we have a .txt file like so (all on one line):
A2.)43@|@C3::#
So we want "A" as key for the value ".)" and "4" as key for the value "@|@" etc.. The number after the key tells us how many characters to read as the value, and the character after is the key for the next item in the dictionary.
The thing I'm struggling with is writing the loop. I'm thinking that we might want to iterate over the length of the file using a for loop. But I don't really know how to proceed.
python file dictionary file-read
python file dictionary file-read
edited Nov 12 '18 at 23:18
martineau
65.9k989177
asked Nov 12 '18 at 22:28
bullebullebagarn
162
edited Nov 12 '18 at 23:18
martineau
65.9k989177
asked Nov 12 '18 at 22:28
bullebullebagarn
162
edited Nov 12 '18 at 23:18
martineau
65.9k989177
edited Nov 12 '18 at 23:18
martineau
65.9k989177
edited Nov 12 '18 at 23:18
martineau
65.9k989177
65.9k989177
asked Nov 12 '18 at 22:28
bullebullebagarn
162
asked Nov 12 '18 at 22:28
bullebullebagarn
162
asked Nov 12 '18 at 22:28
bullebullebagarn
162
162
1
Awhileloop would be better so you can increment the index variable arbitrarily (or check for end of file instead) to process all characters of a value at once.
– Michael Butscher
Nov 12 '18 at 22:31
Here's a hint: go to class and read your notes.
– Julien
Nov 12 '18 at 22:34
Why would the "3" character following the "4" be skipped?
– martineau
Nov 12 '18 at 23:21
add a comment |
1
Awhileloop would be better so you can increment the index variable arbitrarily (or check for end of file instead) to process all characters of a value at once.
– Michael Butscher
Nov 12 '18 at 22:31
Here's a hint: go to class and read your notes.
– Julien
Nov 12 '18 at 22:34
Why would the "3" character following the "4" be skipped?
– martineau
Nov 12 '18 at 23:21
1
1
A
while loop would be better so you can increment the index variable arbitrarily (or check for end of file instead) to process all characters of a value at once.– Michael Butscher
Nov 12 '18 at 22:31
A
while loop would be better so you can increment the index variable arbitrarily (or check for end of file instead) to process all characters of a value at once.– Michael Butscher
Nov 12 '18 at 22:31
Here's a hint: go to class and read your notes.
– Julien
Nov 12 '18 at 22:34
Here's a hint: go to class and read your notes.
– Julien
Nov 12 '18 at 22:34
Why would the "3" character following the "4" be skipped?
– martineau
Nov 12 '18 at 23:21
Why would the "3" character following the "4" be skipped?
– martineau
Nov 12 '18 at 23:21
add a comment |
1 Answer
1
active
oldest
votes
This worked for me
stringText = "A2.)43@|@C3::#"
i=0
myDictionary =
while True:
try:
#First we grab the key character using i
keyCharacter = stringText[i]
#Then we grab the next character which will tell us how many characters they value will have
# We also convert it to integer for future use
valueLength = int(stringText[i+1])
#Then we grab the value by slicing the string
valueCharacters = stringText[i+2:i+2+valueLength]
#We add this to the dictionary
myDictionary[keyCharacter] = valueCharacters
#We update i to continue where we left off
i = i+2+valueLength
except IndexError:
break
print myDictionary
Instead of the "try and except" you could also see how long that string is and do and if statement to break the loop when i is bigger than the length of the string.
answered Nov 12 '18 at 23:30
Alvaro Bataller
515
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
This worked for me
stringText = "A2.)43@|@C3::#"
i=0
myDictionary =
while True:
try:
#First we grab the key character using i
keyCharacter = stringText[i]
#Then we grab the next character which will tell us how many characters they value will have
# We also convert it to integer for future use
valueLength = int(stringText[i+1])
#Then we grab the value by slicing the string
valueCharacters = stringText[i+2:i+2+valueLength]
#We add this to the dictionary
myDictionary[keyCharacter] = valueCharacters
#We update i to continue where we left off
i = i+2+valueLength
except IndexError:
break
print myDictionary
Instead of the "try and except" you could also see how long that string is and do and if statement to break the loop when i is bigger than the length of the string.
answered Nov 12 '18 at 23:30
Alvaro Bataller
515
add a comment |
This worked for me
stringText = "A2.)43@|@C3::#"
i=0
myDictionary =
while True:
try:
#First we grab the key character using i
keyCharacter = stringText[i]
#Then we grab the next character which will tell us how many characters they value will have
# We also convert it to integer for future use
valueLength = int(stringText[i+1])
#Then we grab the value by slicing the string
valueCharacters = stringText[i+2:i+2+valueLength]
#We add this to the dictionary
myDictionary[keyCharacter] = valueCharacters
#We update i to continue where we left off
i = i+2+valueLength
except IndexError:
break
print myDictionary
Instead of the "try and except" you could also see how long that string is and do and if statement to break the loop when i is bigger than the length of the string.
answered Nov 12 '18 at 23:30
Alvaro Bataller
515
add a comment |
This worked for me
stringText = "A2.)43@|@C3::#"
i=0
myDictionary =
while True:
try:
#First we grab the key character using i
keyCharacter = stringText[i]
#Then we grab the next character which will tell us how many characters they value will have
# We also convert it to integer for future use
valueLength = int(stringText[i+1])
#Then we grab the value by slicing the string
valueCharacters = stringText[i+2:i+2+valueLength]
#We add this to the dictionary
myDictionary[keyCharacter] = valueCharacters
#We update i to continue where we left off
i = i+2+valueLength
except IndexError:
break
print myDictionary
Instead of the "try and except" you could also see how long that string is and do and if statement to break the loop when i is bigger than the length of the string.
answered Nov 12 '18 at 23:30
Alvaro Bataller
515
This worked for me
stringText = "A2.)43@|@C3::#"
i=0
myDictionary =
while True:
try:
#First we grab the key character using i
keyCharacter = stringText[i]
#Then we grab the next character which will tell us how many characters they value will have
# We also convert it to integer for future use
valueLength = int(stringText[i+1])
#Then we grab the value by slicing the string
valueCharacters = stringText[i+2:i+2+valueLength]
#We add this to the dictionary
myDictionary[keyCharacter] = valueCharacters
#We update i to continue where we left off
i = i+2+valueLength
except IndexError:
break
print myDictionary
Instead of the "try and except" you could also see how long that string is and do and if statement to break the loop when i is bigger than the length of the string.
answered Nov 12 '18 at 23:30
Alvaro Bataller
515
answered Nov 12 '18 at 23:30
Alvaro Bataller
515
answered Nov 12 '18 at 23:30
Alvaro Bataller
515
answered Nov 12 '18 at 23:30
Alvaro Bataller
515
515
add a comment |
add a comment |
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1
A
whileloop would be better so you can increment the index variable arbitrarily (or check for end of file instead) to process all characters of a value at once.– Michael Butscher
Nov 12 '18 at 22:31
Here's a hint: go to class and read your notes.
– Julien
Nov 12 '18 at 22:34
Why would the "3" character following the "4" be skipped?
– martineau
Nov 12 '18 at 23:21