Aug 27, 2018
C++ Basics and Python
Python
dictionary get()
Method
get()
MethodThe method get()
returns a value for the given key. If key is not available then returns default value None
.
dict.get(key, default = None)
key − This is the
Key
to be searched in the dictionary.default − This is the
Value
to be returned in case key does not exist.
dict = {'Name': 'Zabra', 'Age': 7}
print "Value : %s" % dict.get('Age')
print "Value : %s" % dict.get('Education', "Never")
Output:
Value : 7
Value : Never
C++
abs()
abs()
Returns the absolute value of parameter n
.
/* abs example */
#include <stdio.h> /* printf */
#include <stdlib.h> /* abs */
int main ()
{
int n,m;
n=abs(23);
m=abs(-11);
printf ("n=%d\n",n);
printf ("m=%d\n",m);
return 0;
}
Output
n=23
m=11
std::tolower(charT c, const locale& loc)
std::tolower(charT c, const locale& loc)
Converts parameter c
to its lowercase equivalent if c
is an uppercase letter and has a lowercase equivalent, as determined by the ctype facet of locale loc
. If no such conversion is possible, the value returned is c
unchanged.
// tolower example (C++)
#include <iostream> // std::cout
#include <string> // std::string
#include <locale> // std::locale, std::tolower
int main ()
{
std::locale loc;
std::string str="Test String.\n";
for (std::string::size_type i=0; i<str.length(); ++i)
std::cout << std::tolower(str[i],loc);
return 0;
}
std::string::erase()
std::string::erase()
sequence (1) string& erase (size_t pos = 0, size_t len = npos);
character (2) iterator erase (const_iterator p);
range (3) iterator erase (const_iterator first, const_iterator last);
Erases part of the string, reducing its length
sequence: Erases the portion of the string value that begins at the character position
pos
and spanslen
characters (or until the end of the string, if either the content is too short or iflen
is string::npos. Notice that the default argument erases all characters in the string (like member function clear).character: Erases the character pointed by
p
.range: Erases the sequence of characters in the range
[first,last)
.
string remove_rubbish(string s) {
auto is_rubbish = [](char c) {
return ispunct(c) || isspace(c);
};
// remove spaces and puctuations
s.erase(std::remove_if(s.begin(),
s.end(),
is_rubbish),
s.end());
return s;
}
std::string::substr()
std::string::substr()
string substr (size_t pos = 0, size_t len = npos) const;
Returns a newly constructed string object with its value initialized to a copy of a substring of this object.
The substring is the portion of the object that starts at character position pos
and spans len
characters (or until the end of the string, whichever comes first).
pos
Position of the first character to be copied as a substring. If this is equal to the string length, the function returns an empty string. If this is greater than the string length, it throws out_of_range. Note: The first character is denoted by a value of
0
(not 1).
len
Number of characters to include in the substring (if the string is shorter, as many characters as possible are used). A value of string::npos indicates all characters until the end of the string.
#include <iostream>
#include <string>
int main ()
{
std::string str="We think in generalities, but we live in details.";
// (quoting Alfred N. Whitehead)
std::string str2 = str.substr(3,5); // "think"
std::size_t pos = str.find("live"); // position of "live" in str
std::string str3 = str.substr(pos); // get from "live" to the end
std::cout << str2 << ' ' << str3 << '\n';
return 0;
}
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