Arrays String
As we declare string, we can use it as Array of String.
string = ‘GoHired’
print string[0]
>> G
PS : To show OutPut we have used >> sign
string = ‘GoHired’
print ‘string at 0 ‘ + string[0]
print ‘string at 6 ‘ + string[6]
>>string at 0 G
>>string at 6 d
To print String from back, just use negative indexes.
example
string = ‘GoHired’
print ‘string at -1 ‘ + string[-1]
print ‘string at -2 ‘ + string[-2]
print ‘string at -3 ‘ + string[-3]
>> string at -1 d >> string at -2 e >> string at -3 r
Architecture of String
+—+—+—+—+—+—+—+
| G | o | H | i | r | e | d |
+—+—+—+—+—+—+—+
0 1 2 3 4 5 6 7
-7 -6 -5 -4 -3 -2 -1 0
SubString
print ‘string between 0 to 3 ‘ + string[0:3]
# characters from position 0 (included) to 3 (excluded)
>> GoH
Python strings cannot be changed — they are immutable
string[0] = ‘D’
#Error
TypeError: ‘str’ object does not support item assignment
If you need a different string, you should create a new one:
print ‘D’ + string [1:]
>> DoHired
print 'Home' + string [:2]
>> HomeGo
Length Function
print len(string)
x = len(string)
print “string[0:len(string)] = ” + string[0:len(string)]
print “string[0:x] = ” + string[0:x]
>> 7 >> string[0:len(string)] = GoHired >> string[0:x] = GoHired
Other Functions and its OutPuts
capitalize() & lower()
# capitalize() : First character capitalized and the rest lowercased.
# lower() : Converts all uppercase letters in string to lowercase
str=’inDia’
print str.capitalize()
>> India
# See ‘D’
center(width, fillchar)
Returns a space-padded string with the original string centered to a total of width columns
str=’india’
print “str.center(10, ‘*’) : “, str.center(10, ‘*’)
>> str.center(10, '*') : **india***
count(str, start,end)
Counts how many times str occurs in string or in a substring of string if starting index beg and ending index end are given
str = “This is GoHired Site !!!”;
sub = “i”;
print “str.count(“+ sub + “, 4, 40) : “, str.count(sub, 4, 40)
sub = “DD”;
print “str.count(“+ sub +”) : “, str.count(sub)
>> str.count(i, 4, 40) : 3 >> str.count(DD) : 0
Encode Decode(encoding=’UTF-8′,errors=’strict’)
errors — This may be given to set a different error handling scheme. The default for errors is ‘strict’, meaning that encoding errors raise a UnicodeError.
Other possible values are ‘ignore’, ‘replace’, ‘xmlcharrefreplace’, ‘backslashreplace’ and any other name registered via codecs.register_error().
str = “This is GoHired Site !!!”;
str = str.encode(‘base64′,’strict’);
print “Encoded String: ” + str;
print “Decoded String: ” + str.decode(‘base64′,’strict’)
>> Encoded String: VGhpcyBpcyBHb0hpcmVkIFNpdGUgISEh >> Decoded String: This is GoHired Site !!!
Other Encoding list : https://docs.python.org/2/library/codecs.html#standard-encodings
Find(str, beg,end)
if str occurs in string or in a substring of string if starting index beg and ending index end are given returns index if found and -1 otherwise
str1 = “This is GoHired Site !!!”;
str2 = “Go”;
print str1.find(str2);
print str1.find(str2, 5);
print str1.find(str2, 30);
str2 = “Go”;
print str1.find(str2);
print str1.find(str2, 5);
print str1.find(str2, 30);
>> 8 >> 8 >> -1
join(sequence)
str = ” “;
seq = (“Welcome”,”to” ,”Go”,”Hired”); # This is sequence of strings.
print str.join( seq );
>> Welcome to Go Hired
maketrans() & translate(trantab)
maketrans() : Returns a translation table to be used in translate function.
translate(table, deletechars=””) Translates string according to translation table str(256 chars), removing those in the del string
from string import maketrans # Required to call maketrans function.
intab = “aeiou”
outtab = “12345”
trantab = maketrans(intab, outtab)
str1 = “Welcome to Go Hired !!!”;
print str1.translate(trantab);
print str1.translate(trantab, ‘xm’);
>> W2lc4m2 t4 G4 H3r2d !!! >> W2lc42 t4 G4 H3r2d !!!
You can see running functions at : http://ideone.com/OpFECC