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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.
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])
This question already has answers here:
Converting a list to a set changes element order
(16 answers)
Closed 3 years ago.
I have a set of characters (x) that is ordered as I need it:
{'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'}
However, when I attempt to convert these back to a string using the .join() function:
return ' '.join(x)
The characters are being randomly reordered:
'c g e w i z n t l a q h p d f v m k b x u r j o y'
Any ideas as to what's going on here?
Sets don't "promise" to maintain order, sometimes they do, but they shouldn't be used with a dependency on it. Furthermore, consider using the following:
alpha = ['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']
Then:
return " ".join(alpha)
However, if you only care about it being in alphabetical and want to use a set you can force it to be sorted before using the join function...
return " ".join(sorted(x))
Good luck!
Sets and dictionaries are unordered (pre Python 3.7). Their exact implementation involves hashtables and can be a little complicated. However, suffice it to say that the order you put elements into the set does not determine the order they are stored.
You can use OrderedDict or you can convert the set to a list, sort, and go from there.
I joined multiple files using Pandas join() but now want to rename a few of the duplicate columns. But when I specify the indices to rename a few columns, more than the specified no. of columns are being renamed.
Input CSV files have the format
F1.csv
A,B,C,D,E,F
1,4,5,6,7,8
2,1,3,4,5,6
3,4,1,5,1,8
4,5,1,5,6,7
F2.csv
A,B,C,M,N
1,4,5,6,7
2,1,3,4,5
3,4,1,5,1
4,5,1,5,6
F3.csv
A,B,C,X,Y,Z
1,4,5,6,7,8
2,1,3,4,5,6
3,4,1,5,1,8
4,5,1,5,6,7
F4.csv
A,B,C,T,Q,R
1,4,5,6,7,8
2,1,3,4,5,6
3,4,1,5,1,8
4,5,1,5,6,7
And my code
data = None
for f in filelist:
if data is None:
data = pandas.read_csv(f, index_col='A')
else:
data = data.join(pandas.read_csv(f, index_col='A'), lsuffix='_left', rsuffix='_right', how=join_type)
print(list(data))
new_names =["HH","XX"]
old_names = data.columns[[0,1]]
data.rename(columns=dict(zip(old_names, new_names)), inplace=True)
print(list(data_union))
The first print gives the output
['B_left', 'C_left', 'D', 'E', 'F', 'B_right', 'C_right', 'M', 'N', 'B_left', 'C_left', 'X', 'Y', 'Z', 'B_right', 'C_right', 'T', 'Q', 'R']
And print after renaming gives
['HH', 'XX', 'D', 'E', 'F', 'B_right', 'C_right', 'M', 'N', 'HH', 'XX', 'X', 'Y', 'Z', 'B_right', 'C_right', 'T', 'Q', 'R']
My problem is instead of renaming columns at indices 0 and 1 alone, it is changing indices 10 and 11 too. Could anyone help me with this? I am new to Pandas and not able to figure this out. Thanks,