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how to extract a sentence from string in python using simple for loop?

str1 = "srbGIE JLWokvQeR DPhyItWhYolnz"
Like I want to extract I Love Python from this string. But I am not getting how to.
I tried to loop in str1 but not successful.
i = str1 .index("I")
for letter in range(i, len(mystery11)):
if letter != " ":
letter = letter+2
else:
letter = letter+3
print(mystery11[letter], end = "")

In your for loop letter is an integer. In the the first line of the loop you need to compare mystery[11] with " ":
if mystery11[letter] != " ":

You can use a dict here, and have char->freq mapping of the sentence in it and create a hash table.
After that you can simply iterate over the string and check if the character is present in the hash or not, and if it is present then check if its count is greater than 1 or not.

Don't know if this will solve all your problems, but you're running your loop over the indices of the string, This means that your variable letter is an integer not a char. Then, letter != " " is always true. To select the current letter you need to do string[letter]. For example,
if mystery11[letter] != " ":
...

Here's how I'd go about:
Understand the pattern of the input: words are separated by blank spaces and we should get every other letter after the first uppercase one.
Convert string into a list;
Find the first uppercase letter of each element and add one so we are indexing the next one;
Get every other char from each word;
Join the list back into a string;
Print :D
Here's the code:
def first_uppercase(str):
for i in range(0, len(str)):
if word[i].istitle():
return i
return -1
def decode_every_other(str, i):
return word[i::2]
str1 = "srbGIE JLWokvQeR DPhyItWhYolnz"
# 1
sentence = str1.split()
clean_sentence = []
for word in sentence:
# 2
start = first_uppercase(word) + 1
# 3
clean_sentence.append(decode_every_other(word, start))
# 4
clean_sentence = ' '.join(clean_sentence)
print("Input: " + str1)
print("Output: " + clean_sentence)
This is what I ended up with:
Input: srbGIE JLWokvQeR DPhyItWhYolnz
Output: I Love Python
I've added some links to the steps so you can read more if you want to.

def split(word):
return [char for char in word]
a = input("Enter the original string to match:- ")
b = input("Enter the string to lookup for:- ")
c = split(a)
d = split(b)
e = []
for i in c:
if i in d:
e.append(i)
if e == c:
final_string = "".join(e)
print("Congrats!! It's there and here it is:- ", final_string)
else:
print("Sorry, the string is not present there!!")

Splitting String Variable Into New Variables

I am creating a script that splits the user input into letters, I have gotten this part down, however, how do I turn these separated letters into individual variables?
message = input("Enter Message) ")
list = list(message)
print(list)
Whilst this does print out the typed string into letters, I want to know how to turn those split letters into their own variables. e.g (h, e, l, l, o) Is there a way that I can, for example, only print the first letter or the second letter? (so that the letters are split into their own variables)

You can treat the list as a set 'own variables' (accessing them by index).
message = input("Enter Message) ")
l = list(message) # do not use reserved words, as 'list' for variable names
print(l)
print(l[0]) # prints the 1st letter
print(l[1]) # prints the 2nd letter
print(l[-1]) # prints the last letter
print(l[-2]) # prints the letter prior to the last

Just adding some examples:
message = input("Enter Message) ")
message_characters = list(message) # do not use single characters as variable names
for i, char in enumerate(message_characters):
print(f'The {i}{"th" if i>2 or i==0 else "nd" if i==2 else "st"} character is {char}')
# Though note that strings are also iterable:
for i, char in enumerate(message):
print(f'The {i}{"th" if i>2 or i==0 else "nd" if i==2 else "st"} character is {char}')

Python:Taking the first character without Lists

My code is about creating a password using the first character/digit of every word/number as a character in a sentence/phrase and printing it just as so.
Example: Stop and smell the 350 "roses". -> Sast3r. (Ignoring
quotations using r instead)
This would be very easy using lists, but you cannot use them in this assignment for my code. So, I don't know what to do now after what I have done so far
Function:
def create_password(phrase):
q = "'" # quotations
dq = '"' # double quotes
password = phrase[0]
for i in phrase:
x = phrase.find(" ")
if i.isalnum:
password += phrase[x + 1]
elif x == q or x == dq:
password += phrase[x + 2]
return password
Main:
# Imports
from credentials import create_password
# Inputs
phrase = str(input("Enter a sentence or phrase: "))
# Outputs
password = create_password(phrase)
print(password)

I think it is more straightforward to walk through the entire phrase without worrying about splitting on spaces. Instead keep track of whether or not you've just seen a space. You only want to add the character after just seeing a space.
def create_password(phrase):
q = "'" # quotations
dq = '"' # double quotes
#Initialize the password to be an empty string
password = ""
#We are at the start of a new word (want to add first index to password)
new_word = True
#Walk through every character in the phrase
for char in phrase:
#We only want to add char to password if the following is all true:
#(1) It's a letter or number
#(2) It's at the start of a new word
#(3) It's not a single quote
#(4) It's not a double quote
if char.isalnum and new_word:
if char != q and char != dq:
password += char
new_word = False #<-- After adding char, we are not at a new word
#If we see a space then we are going to be at a new word
elif char == " ":
new_word = True
return password
p = create_password('Stop and smell the 350 "roses"')
print(p)
Output:
Sast3r

You're definitely on the right track! Using the str.find() method is definitely the way to go!
However, you need to understand what the str.find() method does. Look at the signature:
str.find(sub [,start [,end) -> int
# sub -> character to find
# start -> where the function should start looking in the string
# end -> where the function should stop looking
# Returns a number, which is the place it found the character.
# If it didn't find anything, then return -1.
Without telling the function where to start, it will always find the first occurrence of the character in the string. It won't know that you're going through each character of the string.
So let's change it up a little bit:
for char_index in xrange(len(phrase)):
# Tell the method to look after char_index: we've already looked before this!
x = phrase.find(' ', char_index) index
if phrase[x+1].isalnum(): # It's a function, notice the brackets?
password += phrase[x + 1]
elif phrase[x+2] == q or phrase[x+2] == dq:
password += phrase[x + 2]
Hopefully, this should get your desired password.

Give priority to the use of built-in function, for example, every time you find the location of space, then why not directly in accordance with the space for spilt function, so that the string directly to the character list, each element is a word, and then remove each element in the list.
def create_password(phrase):
password = ''
phrase_list = phrase.split(' ')
print (phrase_list)
for i in phrase_list:
print (i[0])
password += i[0]
return password
if __name__ == '__main__':
# Inputs
phrase = str(input("Enter a sentence or phrase: "))
# Outputs
password = create_password(phrase)
print(password)

Try taking the first character in the string, and then every character that follows a space. It looks like you have the right idea.

How to check for valid sequence input?

import re
def check_input():
while True:
try:
sequence = raw_input("Please input:")
if sequence = [a,t,c,g]: # checking for valid input
continue
else:
print("invalid input, sequence coule only contain the "
"following letters (a,t,c,g)"):
check_input()
I basically want the script to check the user's input whether it contains only these four letters (a,t,c,g). If their input contains anything other than that four letters, it could print that second statement and prompt the user to input again. I saw there are similar questions and I already tried to change my script according to those posts but it still gives me the invalid syntax error at the if < sequence position. Anyone knows what's wrong here?

You need to iterate over every letter in the input and check if it is in the set of allowed letters, like this:
sequence = raw_input("Please input:")
for letter in sequence:
if letter not in "atcg":
print("invalid input, sequence coule only contain the following letters (a,t,c,g)")
When you discover that the sequence is invalid, you could choose to end the check by using a break statement after the print, or you could count how many invalid letters are allowed.

Your function must check and give user whether True or False:
def check_input(word):
result = True
for letter in sequene:
if letter in 'atcg':
continue
else:
result = False
break
return result
check_input('atgc')
Error Message:
if check_input('agct'):
continue
else:
print "error message"

You could also use the filter command:
def checkInp():
seq = raw_input("Please input sequence:")
if not filter(lambda m: m not in 'ATGC', seq) == '':
print 'Invalid input characters in sequence: ' + filter(lambda m: m not in 'ATGC', seq)
print 'Pleas'
check_input()
else: return seq

sequence, once input by the user will be a string, so you would need to iterate over each character in the sequence and use in to verify the existence of the character in the accepted characters string. String comparisons in Python are also case sensitive, so you need to match the case of the input to your expected string. I've used uppercase based on your sample input.
def check_input():
sequence = input("Please input:")
sequence.upper()
for letter in sequence:
if letter in 'ATCG':
continue
else:
print("invalid input, sequence could only contain the
following letters: a, t, c or g.")

Soundex algorithm in Python (homework help request)

The US census bureau uses a special encoding called “soundex” to locate information about a person. The soundex is an encoding of surnames (last names) based on the way a surname sounds rather than the way it is spelled. Surnames that sound the same, but are spelled differently, like SMITH and SMYTH, have the same code and are filed together. The soundex coding system was developed so that you can find a surname even though it may have been recorded under various spellings.
In this lab you will design, code, and document a program that produces the soundex code when input with a surname. A user will be prompted for a surname, and the program should output the corresponding code.
Basic Soundex Coding Rules
Every soundex encoding of a surname consists of a letter and three numbers. The letter used is always the first letter of the surname. The numbers are assigned to the remaining letters of the surname according to the soundex guide shown below. Zeroes are added at the end if necessary to always produce a four-character code. Additional letters are disregarded.
Soundex Coding Guide
Soundex assigns a number for various consonants. Consonants that sound alike are assigned the same number:
Number Consonants
1 B, F, P, V 2 C, G, J, K, Q, S, X, Z 3 D, T 4 L 5 M, N 6 R
Soundex disregards the letters A, E, I, O, U, H, W, and Y.
There are 3 additional Soundex Coding Rules that are followed. A good program design would implement these each as one or more separate functions.
Rule 1. Names With Double Letters
If the surname has any double letters, they should be treated as one letter. For example:
Gutierrez is coded G362 (G, 3 for the T, 6 for the first R, second R ignored, 2 for the Z).
Rule 2. Names with Letters Side-by-Side that have the Same Soundex Code Number
If the surname has different letters side-by-side that have the same number in the soundex coding guide, they should be treated as one letter. Examples:
Pfister is coded as P236 (P, F ignored since it is considered same as P, 2 for the S, 3 for the T, 6 for the R).
Jackson is coded as J250 (J, 2 for the C, K ignored same as C, S ignored same as C, 5 for the N, 0 added).
Rule 3. Consonant Separators
3.a. If a vowel (A, E, I, O, U) separates two consonants that have the same soundex code, the consonant to the right of the vowel is coded. Example:
Tymczak is coded as T-522 (T, 5 for the M, 2 for the C, Z ignored (see "Side-by-Side" rule above), 2 for the K). Since the vowel "A" separates the Z and K, the K is coded.
3.b. If "H" or "W" separate two consonants that have the same soundex code, the consonant to the right is not coded. Example:
*Ashcraft is coded A261 (A, 2 for the S, C ignored since same as S with H in between, 6 for the R, 1 for the F). It is not coded A226.
So far this is my code:
surname = raw_input("Please enter surname:")
outstring = ""
outstring = outstring + surname[0]
for i in range (1, len(surname)):
nextletter = surname[i]
if nextletter in ['B','F','P','V']:
outstring = outstring + '1'
elif nextletter in ['C','G','J','K','Q','S','X','Z']:
outstring = outstring + '2'
elif nextletter in ['D','T']:
outstring = outstring + '3'
elif nextletter in ['L']:
outstring = outstring + '4'
elif nextletter in ['M','N']:
outstring = outstring + '5'
elif nextletter in ['R']:
outstring = outstring + '6'
print outstring
sufficiently does what it is asked to, I am just not sure how to code the three rules. That is where I need help. So, any help is appreciated.

I would suggest you try the following.
Store a CurrentCoded and LastCoded variable to work with before appended to your output
Break down the system into useful functions, such as
Boolean IsVowel(Char)
Int Coded(Char)
Boolean IsRule1(Char, Char)
Once you break it down nicely it should become easier to manage.

This is hardly perfect (for instance, it produces the wrong result if the input doesn't start with a letter), and it doesn't implement the rules as independently-testable functions, so it's not really going to serve as an answer to the homework question. But this is how I'd implement it:
>>> def soundex_prepare(s):
"""Prepare string for Soundex encoding.
Remove non-alpha characters (and the not-of-interest W/H/Y),
convert to upper case, and remove all runs of repeated letters."""
p = re.compile("[^a-gi-vxz]", re.IGNORECASE)
s = re.sub(p, "", s).upper()
for c in set(s):
s = re.sub(c + "{2,}", c, s)
return s
>>> def soundex_encode(s):
"""Encode a name string using the Soundex algorithm."""
result = s[0].upper()
s = soundex_prepare(s[1:])
letters = 'ABCDEFGIJKLMNOPQRSTUVXZ'
codes = '.123.12.22455.12623.122'
d = dict(zip(letters, codes))
prev_code=""
for c in s:
code = d[c]
if code != "." and code != prev_code:
result += code
if len(result) >= 4: break
prev_code = code
return (result + "0000")[:4]

surname = input("Enter surname of the author: ") #asks user to input the author's surname
while surname != "": #initiates a while loop thats loops on as long as the input is not equal to an empty line
str_ini = surname[0] #denotes the initial letter of the surname string
mod_str1 = surname[1:] #denotes modified string excluding the first letter of the surname
import re #importing re module to access the sub function
mod_str2 = re.sub(r'[aeiouyhwAEIOUYHW]', '', mod_str1) #eliminating any instances of the given letters
mod_str21 = re.sub(r'[bfpvBFPV]', '1', mod_str2)
mod_str22 = re.sub(r'[cgjkqsxzCGJKQSXZ]', '2', mod_str21)
mod_str23 = re.sub(r'[dtDT]', '3', mod_str22)
mod_str24 = re.sub(r'[lL]', '4', mod_str23)
mod_str25 = re.sub(r'[mnMN]', '5', mod_str24)
mod_str26 = re.sub(r'[rR]', '6', mod_str25)
#substituting given letters with specific numbers as required by the soundex algorithm
mod_str3 = str_ini.upper()+mod_str26 #appending the surname initial with the remaining modified trunk
import itertools #importing itertools module to access the groupby function
mod_str4 = ''.join(char for char, rep in itertools.groupby(mod_str3))
#grouping each character of the string into individual characters
#removing sequences of identical numbers with a single number
#joining the individually grouped characters into a string
mod_str5 = (mod_str4[:4]) #setting character limit of the modified string upto the fourth place
if len (mod_str5) == 1:
print (mod_str5 + "000\n")
elif len (mod_str5) == 2:
print (mod_str5 + "00\n")
elif len (mod_str5) == 3:
print (mod_str5 + "0\n")
else:
print (mod_str5 + "\n")
#using if, elif and else arguments for padding with trailing zeros
print ("Press enter to exit") #specification for the interactor, to press enter (i.e., equivalent to a new line for breaking the while loop) when he wants to exit the program
surname = input("Enter surname of the author: ") #asking next input from the user if he wants to carry on
exit(0) #exiting the program at the break of the while loop