|
s1 + s2
s1 += s2
|
s1 = "Hello "
s2 = "world"
s = s1 + s2
print(s) # "Hello world"
|
Concatenation of strings means all characters from s1 come first,
and then all characters from s2 |
|
s * n
s *= n
|
s1 = "Ra"
s = s1 * 4
print(s) # "RaRaRaRa"
|
String s repeated n times |
| s1 in s2 |
s1 = "own"
s2 = "brown"
print(s1 in s2) # True
print("ron" in s2) # False
|
Checking that substring s1 is contained in s2 |
| s1 not in s2 |
s1 = "own"
s2 = "brown"
print(s1 not in s2) # False
print("ron" not in s2) # True
|
Checking that substring s1 is not contained in string s2
The same as not (s1 in s2) |
| len(s) |
s = "school"
print(len(s)) # 6
|
String length |
| s[i] |
'school'[2] == 'h'
'school'[-1] == 'l'
s = "star"
print(s[0]) # s
print(s[-3]) # t
|
i-th element of the string,
negative i - for counting from the end |
| s[start:stop:step] |
s = 'school'
print(s[:2]) # 'sc'
print(s[2:5]) # 'hoo'
print(s[::2]) # 'sho'
|
Slice a string |
| s.count(s2, a1, an) |
s = "abracadabra"
print(s.count("a")) # 5
print(s.count("a", 2)) # 4
print(s.count("a", 2, 9)) # 3
s2 = "bra"
print(s.count(s2)) # 2
|
count() method returns the number of occurrences of the substring in the given string. |
s1.find(s2)
s1.rfind(s2) |
s = 'abracadabra'
print(s.find('bra')) # 1
print(s.rfind('bra')) # 8
print(s.find('bar')) # -1
|
The index of the beginning of the first or last occurrence of the substring s2 in s1 (will return -1 if s2 not in s1) |
s.startswith(s2)
s.endswith(s2) |
print('school'.startswith('sc')) # True
print('school'.endswith('ml')) # False |
Checking if s starts with s2
or ends with s2
|
|
s.isdigit()
s.isalpha()
s.isalnum()
|
print('123'.isdigit()) # True
print('12A'.isdigit()) # False
print('abc'.isalpha()) # True
print('ab3'.isalpha()) # False
print('E315'.isalnum()) #True
print('E3 15'.isalnum()) #False
|
Checking that all characters in string s are numbers,
letters (including Cyrillic),
numbers or letters
|
|
s.islower()
s.isupper()
|
print('hi!'.islower()) # True
print("Uralsk".islower()) # False
print('PY123'.isupper()) # True
print('NuR%2'.isupper()) # False
|
Checking that the string s does not contain large letters,
small letters.
Note that for both of these functions, punctuation marks and numbers give True
|
|
s.lower()
s.upper()
|
print('Welcome!'.lower()) # welcome!
print('Welcome!'.upper()) # WELCOME!
|
The string s, in which all letters are converted to lower
or upper case,
are replaced with lower or upper case.
|
|
s.capitalize()
s.title()
|
print('welcome back'.capitalize())
# Welcome back
print('welcome back'.title())
# Welcome Back
|
String s, in which the first letter is uppercase
String s, in which all words will be capitalized.
|
|
s.lstrip()
s.rstrip()
s.strip()
|
print(' Welcome! '.lstrip()) # 'Welcome! '
print(' Welcome! '.rstrip()) # ' Welcome!'
print(' Welcome! '.strip()) # 'Welcome!'
|
String s with whitespace characters (spaces, tabs) removed from the beginning,
end,
or both sides
|
|
s.ljust(k, c)
s.rjust(k, c)
|
print('Comment'.ljust(10, '.'))
# Comment...
print('Comment'.rjust(10, '.'))
# ...Comment
|
Adds the required amount to the left
or right
characters c so that the length s reaches k
|
|
s.join(a)
|
print(' '.join(['Computer', 'science']))
# Computer science
|
Concatenates (joins) strings from list a through s |
|
s.split(s2)
|
s = "Computer science"
print(s.split()) # ["Computer", "science"]
print(s.split('e')) # ["Comput", "r sci", "nc"]
print("12:25".split(":")) # ["12", "25"]
|
List of all words of string s (substrings separated by strings s2) |
|
s.replace(s2, s3)
|
s = "School"
print(s.replace('o', 'e')) # Scheel
print(s.replace('o', 'e', 1)) # Scheol
|
String s, in which all occurrences of s2 are replaced by s3
There is an optional third parameter, with which you can specify how many times to replace |
|
list(s)
|
s = "School"
print(list(s)) # ['S', 'c', 'h', 'o', 'o', 'l']
|
List of characters from string s |
|
bool(s)
|
s1 = "something"
s2 = ""
print(bool(s1)) # True
print(bool(s2)) # False
|
Checking that the string is not empty (returns True if not empty and False otherwise) |
|
int(s)
float(s)
|
s = "50"
print(int(s) + 4) # 54
print(float(s) + 4) # 54.0
print(int("54A")) # ValueError: invalid literal for int() with base 10: '54A'
|
If string s contains an integer or
(fractional) number,
get this number, otherwise it's an error |
|
str(x)
|
n = 37
print(str(n) + "2") # 372
|
Convert any object x as a string |