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I am trying to print a python list using join after it has randomly selected a specified amount of characters. What I want is for it to print all characters beside each other instead of printing each character on a separate line. Everything works fine up until my for statement, if I print out password_letters it will print (on separate lines) the specified amount based on nr_letters. All I want is to join/concatenate the specified letters onto one line. I have followed the documentation on here and some on google, but I still can't find where I have gone wrong.
Please help me find where I have gone wrong in the below code:
import random
letters = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z']
nr_letters= int(input("How many letters would you like in your password?\n"))
password_letters = random.sample(letters, nr_letters )
for letter in password_letters:
print("".join(letter))
No need for a loop, just join the list.
print("".join(password_letters))
I want to write a really short script that will help me generate a random/nonsense word with the following qualities:
-Has 8 letters
-First letter is "A"
-Second and Fourth letters are random letters
-Fifth letter is a vowel
-Sixth and Seventh letters are random letters and are the same
-Eighth letter is a vowel that's not "a"
This is what I have tried so far (using all the info I could find and understand online)
firsts = 'A'
seconds = ['a','b','c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']
thirds = ['a', 'e', 'i', 'o', 'u', 'y']
fourths = ['a','b','c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']
fifths = ['a', 'e', 'i', 'o', 'u', 'y']
sixths = sevenths = ['a','b','c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']
eighths = ['e', 'i', 'o', 'u', 'y']
print [''.join(first, second, third, fourth, fifth)
for first in firsts
for second in seconds
for third in thirds
for fourth in fourths
for fifth in fifths
for sixth in sixths
for seventh in sevenths
for eighth in eighths]
However it keeps showing a SyntaxError: invalid syntax after the for and now I have absolutely no idea how to make this work. If possible please look into this for me, thank you so much!
So the magic function you need to know about to pick a random letter is random.choice. You can pass a list into this function and it will give you a random element from that list. It also works with strings because strings are basically a list of chars. Also to make your life easier, use string module. string.ascii_lowercase returns all the letters from a to z in a string so you don't have to type it out. Lastly, you don't use loops to join strings together. Keep it simple. You can just add them together.
import string
from random import choice
first = 'A'
second = choice(string.ascii_lowercase)
third = choice(string.ascii_lowercase)
fourth = choice(string.ascii_lowercase)
fifth = choice("aeiou")
sixthSeventh = choice(string.ascii_lowercase)
eighth = choice("eiou")
word = first + second + third + fourth + fifth + sixthSeventh + sixthSeventh + eighth
print(word)
Try this:
import random
sixth=random.choice(sixths)
s='A'+random.choice(seconds)+random.choice(thirds)+random.choice(fourths)+random.choice(fifths)+sixth+sixth+random.choice(eighths)
print(s)
Output:
Awixonno
Ahiwojjy
etc
There are several things to consider. First, the str.join() method takes in an iterable (e.g. a list), not a bunch of individual elements. Doing
''.join([first, second, third, fourth, fifth])
fixes the program in this respect. If you are using Python 3, print() is a function, and so you should add parentheses around the entire list comprehension.
With the syntax out of the way, let's get to a more interesting problem: Your program constructs every (82255680 !) possible word. This takes a long time and memory. What you want is probably to just pick one. You can of course do this by first constructing all, then picking one at random. It's far cheaper though to pick one letter from each of firsts, seconds, etc. at random and then collecting these. All together then:
import random
firsts = ['A']
seconds = ['a','b','c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']
thirds = ['a', 'e', 'i', 'o', 'u', 'y']
fourths = ['a','b','c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']
fifths = ['a', 'e', 'i', 'o', 'u', 'y']
sixths = sevenths = ['a','b','c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']
eighths = ['e', 'i', 'o', 'u', 'y']
result = ''.join([
random.choice(firsts),
random.choice(seconds),
random.choice(thirds),
random.choice(fourths),
random.choice(fifths),
random.choice(sixths),
random.choice(sevenths),
random.choice(eighths),
])
print(result)
To improve the code from here, try to:
Find a way to generate the "data" in a neater way than writing it out explicitly. As an example:
import string
seconds = list(string.ascii_lowercase) # you don't even need list()!
Instead of having a separate variable firsts, seconds, etc., collect these into a single variable, e.g. a single list containing each original list as a single str with all characters included.
This will implement what you describe. You can make the code neater by putting the choices into an overall list rather than have several different variables, but you will have to explicitly deal with the fact that the sixth and seventh letters are the same; they will not be guaranteed to be the same simply because there are the same choices available for each of them.
The list choices_list could contain sub-lists per your original code, but as you are choosing single characters it will work equally with strings when using random.choice and this also makes the code a bit neater.
import random
choices_list = [
'A',
'abcdefghijklmnopqrstuvwxyz',
'aeiouy',
'abcdefghijklmnopqrstuvwxyz',
'aeiouy',
'abcdefghijklmnopqrstuvwxyz',
'eiouy'
]
letters = [random.choice(choices) for choices in choices_list]
word = ''.join(letters[:6] + letters[5:]) # here the 6th letter gets repeated
print(word)
Some example outputs:
Alaeovve
Aievellu
Ategiwwo
Aeuzykko
Here's the syntax fix:
print(["".join([first, second, third])
for first in firsts
for second in seconds
for third in thirds])
This method might take up a lot of memory.
If I make list for e.g.
lst=['a','b','c','d','e','f','g','h','i','j','k','l','n','o','p','q','s','t','u','v','w','x','y','z']
I want a user to select input only from this given list
def select():
select=''
while guess not in ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'n', 'o', 'p', 'q', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']:
guess=input("select a letter? ")
return (select)
We can use this method but is there any other method so instead of putting the whole list we can put variable assign to that list
You need a while loop to ask the user get input till the input is valid like below:
In [1]: valid_input_lst=['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i',
...: 'j', 'k', 'l', 'n', 'o', 'p', 'q', 's', 't',
...: 'u', 'v', 'w', 'x', 'y', 'z']
In [2]:
In [2]: input_char = None
In [4]: while True:
...: print("Input:")
...: input_char = input()
...: if input_char in valid_input_lst:
...: break
...: print("The input is not valid..\n. It should be one of :{}".format(valid_input_lst))
...:
Input:
sy
The input is not valid..
. It should be one of :['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'n', 'o', 'p', 'q', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']
Input:
x
You probably want something like this:
char = input('Enter a character')
if char not in list:
print("not a valid character")
You can't deny the user from entering anything, you should write software that knows how to handle the possible input.
get inquirer using pip:
pip install inquirer
here is an example
import inquirer
options = [
inquirer.List("option",
message="Select an option ",
choices=["A","B","C","D"],
),
]
select = inquirer.prompt(options)
#you can print option using 'select' variable
I have to print letters from an array backwards. I got all the letters to be backwards but I realized I used the sort method and I'm not allowed to use it. I can't figure out any other way. Any suggestions?
The output should be:
w
v
u
t
.
.
.
g
f
This is the code I have so far:
letter = ['f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w']
letter.sort(reverse=True)
for i in range(len(letter)):
print(letter[i])
letter = ['f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w']
letter[::-1]
OR
reverseletter=letter[::-1]
letters = 'fghijklmnopqrstuvw'
for letter in reversed(letters):
print(letter)
Strings work like lists. A string is a list of characters.
reversed() can be used to reverse the order of a list.
There is no need to use range()
you can use use the built-in function reversed :
print(*reversed(letter), sep='\n')
output:
w
v
u
t
s
r
q
p
o
n
m
l
k
j
i
h
g
f
*reversed(letter) will give as non-keyword arguments all the
letters in reverse order for the print built-in function
the keyword argument sep='\n' will ensure that all the letters will be printed on a separate line
To reverse a list you can use.
Slicing [::-1]
for i in letters[::-1]:
print(i)
You can use reversed.
for i in reversed(letter):
print(i)
Note: reversed spits an iterator.
you can use revered() method to print it in reverse order such as below
letter = ['f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w']
for i in reversed(letter):
print(i)
letterrev=letter[::-1]
for i in letterrev:
print(i)
use this one
You can directly use list indexing or slicing such as:
letter = ['f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w']
print(letter[::-1])
I am attempting to learn Python and am working on an assignment for fun that involves translating "encrypted" messages (it's just the alphabet in reverse). My function is supposed to be able to read in an encoded string and then print out its decoded string equivalent. However, as I am new to Python, I find myself continually running into a type error with trying to use the indices of my lists to give the values. If anyone has any pointers on a better approach or if there is something that I just plain missed, that would be awesome.
def answer(s):
'''
All lowercase letters [a-z] have been swapped with their corresponding values
(e.g. a=z, b=y, c=x, etc.) Uppercase and punctuation characters are unchanged.
Write a program that can take in encrypted input and give the decrypted output
correctly.
'''
word = ""
capsETC = 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',\
'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',\
' ', '?', '\'', '\"', '#', '!', '#', '$', '%', '&', '*', '(', \
') ', '-', '_', '+', '=', '<', '>', '/', '\\'
alphF = 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',\
'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'
alphB = 'z', 'y', 'x', 'w', 'v', 'u', 't', 's', 'r', 'q', 'p', 'o', 'n', 'm',\
'l', 'k', 'j', 'i', 'h', 'g', 'f', 'e', 'd', 'c', 'b', 'a'
for i in s:
if i in capsETC: # if letter is uppercase or punctuation
word = word + i # do nothing
elif i in alphB: # else, do check
for x in alphB: # for each index in alphB
if i == alphB[x]: # if i and index are equal (same letter)
if alphB[x] == alphF[x]: # if indices are equal
newLetter = alphF[x] # new letter equals alpf at index x
str(newLetter) # convert to str?
word = word + newLetter # add to word
print(word)
s = "Yvzs!"
answer(s)
your code is fine, just a few changes (left your old lines as comments)
def answer(s):
word = ""
capsETC = 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',\
'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',\
' ', '?', '\'', '\"', '#', '!', '#', '$', '%', '&', '*', '(', \
') ', '-', '_', '+', '=', '<', '>', '/', '\\'
alphF = 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',\
'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'
alphB = 'z', 'y', 'x', 'w', 'v', 'u', 't', 's', 'r', 'q', 'p', 'o', 'n', 'm',\
'l', 'k', 'j', 'i', 'h', 'g', 'f', 'e', 'd', 'c', 'b', 'a'
for i in s:
if i in capsETC: # if letter is uppercase or punctuation
word = word + i # do nothing
elif i in alphB: # else, do check
for x in range(len(alphB)): # for each index in alphB
if i == alphB[x]: # if i and index are equal (same letter)
# if alphB[x] == alphF[x]: # if indices are equal
newLetter = alphF[x] # new letter equals alpf at index x
# str(newLetter) # convert to str?
word = word + newLetter # add to word
return word
s = "Yvzs!"
print(s)
print(answer(s))
ouput
Yvzs!
Yeah!
of course you can make it a lot simple and python's way... but wanted to change your code as little as possible
Your current issue is that you are trying to use letters as indices. To fix your current approach, you could use enumerate while looping through each of your strings.
If you want a much simpler approach, you can make use of str.maketrans and str.translate. These two builtin functions help easily solve this problem:
import string
unenc = string.ascii_lowercase # abcdefghijklmnopqrstuvwxyz
decd = unenc[::-1] # zyxwvutsrqponmlkjihgfedcba
secrets = str.maketrans(unenc, decd)
s = "Yvzs!"
print(s.translate(secrets))
Output:
Yeah!
If you want a looping approach, you can use try and except along with string.index() to achieve a much simpler loop:
import string
unenc = string.ascii_lowercase # abcdefghijklmnopqrstuvwxyz
decd = unenc[::-1] # zyxwvutsrqponmlkjihgfedcba
s = "Yvzs!"
word = ''
for i in s:
try:
idx = unenc.index(i)
except:
idx = -1
word += decd[idx] if idx != -1 else i
print(word)
Output:
Yeah!