000.py

str = 'stressed'
print(str[::-1])

# -> desserts

Output in reverse order using slices. It's interesting to be able to easily write such operations.

001.py

str = "Patatoku Kashii"
print(str[0:8:2])

# ->Police car

Since the odd number is taken out, step is set to 2.

002.py

str1 = "Police car"
str2 = "taxi"
print(''.join([s1 + s2 for s1, s2 in zip(str1, str2)]))

# ->Patatoku Kashii

At first I thought about looping with ʻindex, It seems that you can handle multiple functions at once by using the zip` function.

003.py

sentense = "Now I need a drink, alcoholic of course, after the heavy lectures involving quantum mechanics."
print([len(item) for item in sentense.replace(',', "").replace('.', "").split(' ')])

# -> [3, 1, 4, 1, 5, 9, 2, 6, 5, 3, 5, 8, 9, 7, 9]

I tried using list comprehension notation. It may be convenient because you can write in a few lines when creating a new list.

004.py

str = "Hi He Lied Because Boron Could Not Oxidize Fluorine. New Nations Might Also Sign Peace Security Clause. Arthur King Can."
str = str.split()
num = [1, 5, 6, 7, 8, 9, 15, 16, 19]
dict = {}

for i_str in range(0, len(str)):
    if i_str + 1 == 12:
        dict[str[11][:3:2]] = 12  # 'Mg'Output of
    elif i_str + 1 in num:
        dict[str[i_str][:1]] = i_str + 1
    else:
        dict[str[i_str][:2]] = i_str + 1
print(dict)

# -> {'H': 1, 'He': 2, 'Li': 3, 'Be': 4, 'B': 5, 'C': 6, 'N': 7, 'O': 8, 'F': 9, 'Ne': 10, 'Na': 11, 'Mg': 12, 'Al': 13, 'Si': 14, 'P': 15, 'S': 16, 'Cl': 17, 'Ar': 18, 'K': 19, 'Ca': 20}

I feel like the code is a little long ... If the rules are followed, the Mg part will be output as Mi and I'm curious, so I'm processing it with the ʻif` statement.

005.py

def n_gram(list, n):
    return ["".join(list[list_i: list_i + n]) for list_i in range(len(list) - n + 1)]

sentence = "I am an NLPer"
print(f"Word bi-gran：  {n_gram(sentence.split(), 2)}")
print(f"Character bi-gram：  {n_gram(sentence, 2)}")

# ->Word bi-gran：  ['Iam', 'aman', 'anNLPer']
#Character bi-gram：  ['I ', ' a', 'am', 'm ', ' a', 'an', 'n ', ' N', 'NL', 'LP', 'Pe', 'er']

Use join to join the elements of the list. Since the word bi-gram and the character bi-gram are doing similar processing, I tried to make it a function, but I feel that I was able to write it well.

006.py

str1 = "paraparaparadise"
str2 = "paragraph"

def n_gram(list, n):
    return {"".join(list[list_i: list_i + n]) for list_i in range(len(list) - n + 1)}

X = n_gram(str1, 2)
Y = n_gram(str2, 2)
print(f"Union:{X | Y}")
print(f"Intersection:{X & Y}")
print(f"Difference set:{X - Y}")

se = {"se"}
print(f"Is se included in X? :{se <= X}")
print(f"Is se included in Y? :{se <= Y}")

# ->Union:{'ph', 'di', 'ar', 'gr', 'ad', 'is', 'se', 'ap', 'pa', 'ra', 'ag'}
#Intersection:{'ra', 'ap', 'ar', 'pa'}
#Difference set:{'is', 'di', 'se', 'ad'}
#Is se included in X? : True
#Is se included in Y? : False

Union () , ʻintersection (), difference () can also be used for union, product, and difference.

007.py

def templete(x, y, z):
    return f"{x}of time{y}Is{z}"

print(templete(12, "temperature", 22.4))

# ->The temperature at 12:00 is 22.4

nothing special.

008.py

def cipher(sentence):
    return "".join([chr(219 - ord(ch)) if ch.islower() else ch for ch in sentence])

sen = "FireWork"
print(cipher(sen))
print(cipher(cipher(sen)))

# -> FrivWlip
#    FireWork

It seems to be Atbash encryption. You can get it back by passing the cipher function twice.

009.py

import random

sentence = "I couldn’t believe that I could actually understand what I was reading : the phenomenal power of the human mind."
new_sent = ""
for item in sentence.split():
    if len(item) > 4:
        new_item = []
        new_item.extend(item[0])
        new_item.extend(random.sample(item[1:-1], len(item) - 2))
        new_item.extend(item[-1])
        item = new_item
    new_sent += "".join(item) + " "

print(new_sent)

# -> I could’nt blveeie that I cuold atlculay utnresnadd what I was renadig : the pamohneenl pewor of the human mdin. 

In addition to random.sample, there is random.shuffle as a function to randomly arrange the elements of the list. The shuffle function sorts the original list, so I think the code can be a little shorter.