Pythonの文字列の詳細

Escape characters
# \\\ Backslash
str1 = "qqq\\qq"
print(str1)
# Output qqq/qq
# \b Backspace
str2 = "qqq\b"
print(str2)
# Output qq
# \' single quotes \"double quotes
str3 = "qq\'qqqqq\""
print(str3)
# Output qq'qqqqqqq"
# \n line feed
str4 = "qqqq\nqq"
print(str4)
# output qqqq
# qq
# \t Tabulator (Tab)
str5 = "a\taa"
print(str5)
# Output a aa

s = "hello world sssss sssssss sssssss"
# s[n] specifies a subscript to read an element in the sequence
print(s[1])
# e
# s[n: m] reads from subscript n to m-1, a number of elements
print(s[0: 4])
# hell
# s[n:] reads from subscript n to the last element
print(s[3:])
# lo world
# s[:m] reads from subscript 0 to m-1 elements
print(s[:5])
# hello
# s[:] means that a copy of the sequence is made
print(s[:])
# hello world
# s[::-1] reverses the entire sequence of elements
print(s[::-1])
# dlrow olleh

# string.split(separator, number of separations)
# Output 26 lowercase letters and invert the output
letters = ""
for x in range(97, 123):
    letters += str(chr(x))
print(letters)
print(" ")
print(letters[::-1])
# ord() returns the ASCII code corresponding to the character
# chr() returns the character corresponding to the ASCII code
# output 26 uppercase letters and invert the output A 65 Z 91
letters2 = ""
for n in range(65, 91):
    letters2 += chr(n) + " "
print(letters2)
print(letters2[::-1].split(" ",5)) # string.split(separator, number of separations)

str = "My name in Zyj hello world"
# capitalize() Only the first initial of the word is capitalized, the rest is lowercase
print(str.capitalize())
# My name in zyj hello world
# lower() converts letters to lowercase
print(str.lower())
# my name in zyj hello world
# upper() converts letters to upper case
print(str.upper())
# MY NAME IN ZYJ HELLO WORLD
# title() capitalize the first letter of each word, lowercase the rest
print(str.title())
# My Name In Zyj Hello World
# islower() isupper() istitle() Determines if the string is in format
print(str.isupper())
# False

str1 = "Myaa namess inddaa Zyjcc helloxx worldbb"
# 1.count.py searches for the number of times a particular string exists
print(str1.count("aa"))
# 2. find string str.find(character or string , start subscript, end subscript) Returns the subscript number when the string was first found
# find() method does not find the substring will return -1
str2 = "My name in Zyj hello world My name in Zyj hello world"
print(str2.find("in", )) # Find the substring in, starting with subscript number 0
print(str2.find("in", 9)) # Find the substring in, starting with subscript number 9
# 3. str.index(character or string, start subscript, end subscript) return the specified string subscript value
print(str2.index("name"))
# index differs from find, index() will return an error if it fails to find, find() will return -1 value
# 4. startswith(character or string, start subscript, end subscript) Determine whether the beginning character of the string contains subcharacters
str3 = "My name in Zyj hello world My name in Zyj hello world"
print(str3.startswith("name", 3)) # True
# 5. str.endswith(character or string , start subscript, end subscript) determine whether the end of the string contains subcharacters
print(str3.endswith("world")) # True