converting string to integer in Python

Question

I was trying to convert a string list to integer in python as follows:

plain = input("string >> ")
string_list = list(plain)
print(string_list)
ASCII = []

for x in range (0, len(string_list)):
    ASCII.append([ord(string_list[x])])

print(ASCII)

for x in range (0, len(ASCII)):
    print(ASCII[x])
    integer_ASCII = type(int(ASCII[x]))
    print(integer_ASCII, end=", ")

but I get this error:

TypeError: int() argument must be a string, a bytes-like object or a number, not 'list'

So is there any other way to convert a string to integer.

Please don’t use tabs when assigning variables or calling methods. It’s unnecessary white space and reduces readibility. — Jacob Lee, Dec 12 '20 at 04:41
['t', 'e', 's', 't'] considering i give input as "test" @rcvaram — shubhanshu-tomar, Dec 12 '20 at 04:47
oh you used it you need to remove `[]` from `ASCII.append([ord(string_list[x])])` — Avishka Dambawinna, Dec 12 '20 at 04:51
"oh you used it you need to remove [] from ASCII.append([ord(string_list[x])]) – Avishka Dambawinna 9 mins ago" @AvishkaDambawinna Yes exactly!! — shubhanshu-tomar, Dec 12 '20 at 05:01

Aryan · Answer 1 · 2020-12-12T05:17:20.213

2

Does this resolve your error?

string_list = list("test")
print(string_list)
ASCII = []

for x in range(0, len(string_list)):
    ASCII.append([ord(string_list[x])])

print(ASCII)

integer_ASCII = []
str_integer_ASCII = []

for x in range(0, len(ASCII)):
    integer_ASCII.append(int(ASCII[x][0]))
    str_integer_ASCII.append(str(ASCII[x][0]))

print("\n")
print("INT LIST VERSION:", integer_ASCII, type(integer_ASCII))
print("STRING LIST VERSION:", str_integer_ASCII, type(str_integer_ASCII))
print("FULL STRING VERSION: ", ' '.join(str_integer_ASCII), type(' '.join(str_integer_ASCII)))

Hope so this information is useful to you!
Happy Coding

edited Dec 12 '20 at 05:17

answered Dec 12 '20 at 04:49

Aryan

1,093
9
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It does convert it to a multi dimensional list but still i want to convert each element in the list to an integer because I want to apply arithmetic operation on those integer values – shubhanshu-tomar Dec 12 '20 at 04:53
So basically you want a list like, ```[116, 101, 115, 116]``` right? – Aryan Dec 12 '20 at 04:58
can I actually apply arithmetic on a list because I need to encrypt the string using rsa – shubhanshu-tomar Dec 12 '20 at 05:00
Well, it's a list full of integers so it be possible to to encrypt. I'm not any encryption expert but as per my perspective a list full of integers should be encrypted. So should i edit the post to make the result- ```[116, 101, 115, 116]```?' – Aryan Dec 12 '20 at 05:03
Since it is converting the list from ['116', '101', '115', '116'] to [116, 101, 115, 116] is it possible to remove the "[ ]" since after the application i need to convert everything back to a string – shubhanshu-tomar Dec 12 '20 at 05:06
when you do ord() it will give int type – Sivaram Rasathurai Dec 12 '20 at 05:06
I can manage converting ['116', '101', '115', '116'] to [116, 101, 115, 116] using map() function but i need to remove the braces – shubhanshu-tomar Dec 12 '20 at 05:07
1

Of course, @shubhanshu-tomar, just like this- first create a str version of the ```integer_ASCII``` variable by appending the string value of the ascii code to after wards join them together like- ```str_integer_ASCII.append(str(ASCII[x][0]))``` then, to get the string version of them, ```' '.join(str_integer_ASCII)``` – Aryan Dec 12 '20 at 05:11
So should i edit the post? @shubhanshu-tomar – Aryan Dec 12 '20 at 05:11

score 2 · Accepted Answer · edited Dec 13 '20 at 12:52

2

instead of ascii value, your are appending a list to ASCII First, we map each string character to ASCII value and convert it into a string type. Then join with the join function.

e = 100
n = 20
text = input("string >>>")
#This will return int ascii values for each character. Here you can do any arithmatic operations
rsa_values = list(map(lambda x:(ord(x)**e) % n , text))#[16, 1, 5, 16]


#TO get the same you can list compression also
rsa_values = [ (ord(x)**e) % n for x in text] #[16, 1, 5, 16]



#if you need to join them as string then use join function.
string_ascii_values = "".join(chr(i) for i in ascii_values)#'\x10\x01\x05\x10'

Update

Based on Copperfield's comment A better way to do following arithmetic operation

(ord(x)**e) % n

is

pow(ord(x), e, n)

rsa_values = [ pow(ord(x), e, n) for x in text] #[16, 1, 5, 16]

edited Dec 13 '20 at 12:52

Copperfield

8,131
3
23
29

answered Dec 12 '20 at 04:49

Sivaram Rasathurai

5,533
3
22
45

This clearly removes the braces and gives the output but how do I perform arithmetical operations on an individual ascii value. – shubhanshu-tomar Dec 12 '20 at 05:20
I will break it step by step and post the answer soon – Sivaram Rasathurai Dec 12 '20 at 05:21
please share the breakdown as soon as possible. Thank you! – shubhanshu-tomar Dec 12 '20 at 05:24
Can you tell some kind of example for your arithmetic expression – Sivaram Rasathurai Dec 12 '20 at 05:26
actually I am trying to encrypt the string using RSA so after converting the string to ascii considering each individual as a variable "c" i wil be then doing `c^e mod(n)` – shubhanshu-tomar Dec 12 '20 at 05:31
e and n are values – Sivaram Rasathurai Dec 12 '20 at 05:36
e and n value are generated randomly i'll share their generation please see https://github.com/theEndurance-del/security for their generation – shubhanshu-tomar Dec 12 '20 at 05:37
You can check right now, I have do it inside the list comprehension for arithmatic operatios for each value – Sivaram Rasathurai Dec 12 '20 at 05:40
1

`(ord(x)**e) % n` for each element we are doing this inside the list comprehension or map function both are valid. – Sivaram Rasathurai Dec 12 '20 at 05:42
yes `(ord(x)**e) % n` this would give a new ascii which we have to convert it back to a complete string is this possible? – shubhanshu-tomar Dec 12 '20 at 05:50
yeah that's possible `''.join(chr(i) for i in ascii_values)' – Sivaram Rasathurai Dec 12 '20 at 05:52
sure then I'll try it out – shubhanshu-tomar Dec 12 '20 at 05:52
1

https://stackoverflow.com/questions/180606/how-do-i-convert-a-list-of-ascii-values-to-a-string-in-python – Sivaram Rasathurai Dec 12 '20 at 05:55
1

when doing `(a**b)%m` is better to use the 3 argument version of pow, `pow(a,b,m)` because this one does modular exponentiation which is more efficient way of calculating that – Copperfield Dec 13 '20 at 00:09

user · Answer 3 · 2020-12-12T05:11:08.540

1

Just use a list comprehension that converts each string in the list into an int:

list_of_ints = [int(x) for x in string_list]

Or if you want the char value of each char in the string (which is what you get from input() -- no need to call list() on it):

list_of_char_values = [ord(x) for x in string]

edited Dec 12 '20 at 05:11

answered Dec 12 '20 at 05:09

user

675
4
11

Minu · Answer 4 · 2020-12-12T05:18:11.503

1

Simply it is possible also. Please find about comprehension python.

>>> [ord(x) for x in 'abcde']
[97, 98, 99, 100, 101]

edited Dec 12 '20 at 05:18

answered Dec 12 '20 at 05:14

Minu

380
2
12

1

when you do ord() it will be int, you don't need to do type cast again – Sivaram Rasathurai Dec 12 '20 at 05:17

score -1 · Answer 5 · answered Dec 12 '20 at 04:50

-1

this seemed to work for me, you have a list inside of a list for each number.

plain = 'test'
string_list = list(plain)
print(string_list)
ASCII = []

for x in range (0, len(string_list)):
    ASCII.append([ord(string_list[x])])

print(ASCII)

for x in range (0, len(ASCII)):
    print(ASCII[x])
    integer_ASCII = type(int(ASCII[x][0]))
    print(integer_ASCII, end=", ")

answered Dec 12 '20 at 04:50

dachil1pil1

61
6

Please don't post same answer multiple times I have posted the same exact solution. – Aryan Dec 12 '20 at 04:51
I'm not downvoting @rcvaram he his clearly copying my post! – Aryan Dec 12 '20 at 05:13
your post wasn't loaded before i posted mine. – dachil1pil1 Dec 12 '20 at 17:45

converting string to integer in Python

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