traversing a string

str="raman";
for i in range(0,len(str)):
    print(str[i]);

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reverse a string

str='raman'
print(str[::-1])
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reverse a string

str="raman";
for i in range(len(str)-1,-1,-1):
    print(str[i]);

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program to read a string and display it in the form

first character  -- last character
second character  -- second last character

str="raman";
l=len(str);
for i in range(0,l):
    print(str[i] , "-", str[l-i-1]);

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String operators

String concatenation operator

str="raman";
str1="deep";
print(str+str1);

String replication operator

str="raman";
print(str*3);

Membership Operators
in operator

str="raman";
print("r" in str);

not in operator

str="raman";
print("r" not in str);

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string slices

str="raman";
print(str[2:4]);

output : ma

str="raman";
print(str[:4]);

output : rama

str="raman";
print(str[4:]);

output : n

str="raman";
print(str[-3:]);

output : man

str="raman";
print(str[:-3]);

output : ra

String functions and methods

capitalize method 

str="raman";
print(str.capitalize());

output : Raman

find method

str="raman";
print(str.find("m"));

output : 2

str="raman";
print(str.isalnum());

output : True

str="raman";
print(str.isalpha());

output : True

str="raman";
print(str.isdigit());

Output : False

str="raman";
print(str.islower());

Output : True

str="raman";
print(str.isspace());

Output : False

str="raman";
print(str.isupper());

Output : False

str="raman";
print(str.lower());

Output : raman

str="raman";
print(str.upper());

Output :RAMAN

str="  raman";
print(str.lstrip());

Output : raman

str="raman     ";
print(str.rstrip());

Output : raman

Program to read a line and give its statistics like:
number of upper case letters:
number of lower case letters
number of alphabets:
number of digits:

str="raman123Raman";
low=0;
up=0;
dig=0;
alp=0;
for a in str:
    if a.islower():
        low+=1;
    elif a.isupper():
        up+=1;
    elif a.isdigit():
        dig+=1;
    if a.isalpha():
        alp+=1;
print("Number of alphabets ", alp);
print("Number of Lower Case Letters ", low);
print("Number of Upper Case Letters ",up);
print("Number of Digits : ",dig);


to find no of spaces and special characters


str=input("Enter a string");
low=0;
up=0;
dig=0;
alp=0;
spaces=0;
spchars=0;
for a in str:
    if a.islower():
        low+=1;
    elif a.isupper():
        up+=1;
    elif a.isdigit():
        dig+=1;
    elif a.isspace():
        spaces+=1;
    else:
        spchars+=1;
    if a.isalpha():
        alp+=1;
print("Number of alphabets ", alp);
print("Number of Lower Case Letters ", low);
print("Number of Upper Case Letters ",up);
print("Number of Digits : ",dig);
print("Number of Special Characters ",spchars);
print("Number of Spaces : ",spaces);