{"id":5733,"date":"2022-01-08T16:25:55","date_gmt":"2022-01-08T15:25:55","guid":{"rendered":"http:\/\/miro.borodziuk.eu\/?p=5733"},"modified":"2024-06-17T19:09:39","modified_gmt":"2024-06-17T17:09:39","slug":"the-print-function","status":"publish","type":"post","link":"http:\/\/miro.borodziuk.eu\/index.php\/2022\/01\/08\/the-print-function\/","title":{"rendered":"The print() function"},"content":{"rendered":"

1. The print()<\/code> function is a built-in<\/strong> function. It prints\/outputs a specified message to the screen\/console window.<\/p>\n

<\/p>\n

2. Built-in functions, contrary to user-defined functions, are always available and don’t have to be imported. Python 3.8 comes with 69 built-in functions. You can find their full list provided in alphabetical order in the Python Standard Library<\/a>.<\/p>\n

3. To call a function (this process is known as function invocation<\/strong> or function call<\/strong>), you need to use the function name followed by parentheses. You can pass arguments into a function by placing them inside the parentheses. You must separate arguments with a comma, e.g.,<\/p>\n

print(\"Hello,\", \"world!\")<\/pre>\n
An “empty” print()<\/code> function outputs an empty line to the screen.<\/p>\n
4. Python strings are delimited with quotes<\/strong>, e.g., \"I am a string\"<\/code> (double quotes), or 'I am a string, too'<\/code> (single quotes).<\/p>\n
5. Computer programs are collections of instructions<\/strong>. An instruction is a command to perform a specific task when executed, e.g., to print a certain message to the screen.<\/p>\n
6. In Python strings the backslash<\/strong> (\\<\/code>) is a special character which announces that the next character has a different meaning, e.g., \\n<\/code> (the newline character<\/strong>) starts a new output line.<\/p>\n
7. Positional arguments<\/strong> are the ones whose meaning is dictated by their position, e.g., the second argument is outputted after the first, the third is outputted after the second, etc.<\/p>\n
8. Keyword arguments<\/strong> are the ones whose meaning is not dictated by their location, but by a special word (keyword) used to identify them.<\/p>\n
9. The end<\/code> and sep<\/code> parameters can be used for formatting the output of the print()<\/code> function. The sep<\/code> parameter specifies the separator between the outputted arguments, e.g.,<\/p>\n
print(\"H\", \"E\", \"L\", \"L\", \"O\", sep=\"-\")<\/pre>\n
whereas the end<\/code> parameter specifies what to print at the end of the print statement.<\/p>\n
 <\/p>\n
Ex. 1<\/p>\n
What is the output of the following code snippet?<\/p>\n
x = \"Monty\" \"Python\"\r\nprint(x)<\/pre>\n
 <\/p>\n
The correct answer is MontyPython<\/code>.<\/p>\n
In Python, you can concatenate literal strings by placing them one after the other. In other words, x = “Monty” “Python” is equal to x = “Monty” + “Python”.<\/p>\n
This implicit concatenation works with string literals, but not with string variables. For example, the following code will generate a SyntaxError exception because it implicitly combines string variables:<\/p>\n
a = \"Monty\"\r\nb = \"Python\"\r\nc = a b # SyntaxError\r\n<\/pre>\n
 <\/p>\n
Ex. 2<\/p>\n
\n
\n
\n
What is the output of the following code snippet?<\/p>\n
\n
\n
x = 2\r\ny = 1\r\nx = y\r\ny -= x\r\n\r\nprint(y, x)<\/pre>\n
\u00a0<\/span><\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n
\n
\n
\n
Correct answer<\/span><\/div>\n
\n
\n
0 1<\/strong><\/code><\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n
\n
\n
Incorrect answer
\n<\/span><\/div>\n
\n
\n
01<\/strong><\/code><\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n
\n
\n
\n
    \n
  • In line 4<\/strong>, the -=<\/strong><\/code> operator combines the arithmetic operator -<\/strong><\/code> with the assignment operator =<\/strong><\/code> :y -= x<\/strong><\/code> is equal to y = y - x<\/strong><\/code>.<\/li>\n
  • In line 6<\/strong>, the print<\/strong><\/code> statement prints the values of y<\/strong><\/code> and x<\/strong><\/code> separated by a space on the screen.<\/li>\n
  • In detail:line 1<\/strong> – x = 2<\/strong><\/code>\n
    line 2<\/strong> – y = 1<\/strong><\/code><\/p>\n
    line 3<\/strong> – x = y<\/strong><\/code> -><\/strong> x = 1<\/strong><\/code><\/p>\n
    line 4<\/strong> – y -= x<\/strong><\/code> -><\/strong> y = y - x<\/strong><\/code> -><\/strong> y = 1 - 1<\/strong><\/code> -><\/strong> y = 0<\/strong><\/code><\/p>\n
    line 6<\/strong> – print(y, x)<\/strong><\/code> -><\/strong> print(0, 1)<\/strong><\/code> -><\/strong> 0 1<\/strong><\/code><\/li>\n<\/ul>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"
    1. The print() function is a built-in function. It prints\/outputs a specified message to the screen\/console window.<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[100],"tags":[],"_links":{"self":[{"href":"http:\/\/miro.borodziuk.eu\/index.php\/wp-json\/wp\/v2\/posts\/5733"}],"collection":[{"href":"http:\/\/miro.borodziuk.eu\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/miro.borodziuk.eu\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/miro.borodziuk.eu\/index.php\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"http:\/\/miro.borodziuk.eu\/index.php\/wp-json\/wp\/v2\/comments?post=5733"}],"version-history":[{"count":7,"href":"http:\/\/miro.borodziuk.eu\/index.php\/wp-json\/wp\/v2\/posts\/5733\/revisions"}],"predecessor-version":[{"id":5894,"href":"http:\/\/miro.borodziuk.eu\/index.php\/wp-json\/wp\/v2\/posts\/5733\/revisions\/5894"}],"wp:attachment":[{"href":"http:\/\/miro.borodziuk.eu\/index.php\/wp-json\/wp\/v2\/media?parent=5733"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/miro.borodziuk.eu\/index.php\/wp-json\/wp\/v2\/categories?post=5733"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/miro.borodziuk.eu\/index.php\/wp-json\/wp\/v2\/tags?post=5733"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}