{"id":130214,"date":"2022-12-02T19:10:56","date_gmt":"2022-12-02T19:10:56","guid":{"rendered":"https:\/\/blog.finxter.com\/?p=948232"},"modified":"2022-12-02T19:10:56","modified_gmt":"2022-12-02T19:10:56","slug":"how-to-convert-octal-string-to-integer-in-python","status":"publish","type":"post","link":"https:\/\/sickgaming.net\/blog\/2022\/12\/02\/how-to-convert-octal-string-to-integer-in-python\/","title":{"rendered":"How to Convert Octal String to Integer in Python"},"content":{"rendered":"\n
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5\/5 – (1 vote) <\/div>\n<\/div>\n
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\"\"<\/figure>\n<\/div>\n

Problem Formulation<\/h2>\n

Given a string in the octal form:<\/p>\n

s = '0o77'\n# or s = '77'<\/pre>\n
How to convert the octal string to an integer in Python?<\/strong><\/p>\n
For example, you want to convert the octal string 'o10'<\/code> to the decimal integer 8<\/code>. <\/p>\n
Here are a few other examples:<\/p>\n
\n\n\n\n\n\n\n\n\n\n\n\n
Octal String<\/th>\nDecimal<\/th>\n<\/tr>\n<\/thead>\n
'0o0'<\/code><\/td>\n0<\/td>\n<\/tr>\n
'0o4'<\/code><\/td>\n4<\/td>\n<\/tr>\n
'0o10'<\/code><\/td>\n8<\/td>\n<\/tr>\n
'0o14'<\/code><\/td>\n12<\/td>\n<\/tr>\n
'0o20'<\/code><\/td>\n16<\/td>\n<\/tr>\n
'0o77'<\/code><\/td>\n63<\/td>\n<\/tr>\n
'0o77777'<\/code><\/td>\n32767<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/figure>\n
Oct String to Integer using int() with Base 8<\/h2>\n
To convert an octal string to an integer, pass the string as a first argument into Python’s built-in int()<\/code><\/a> function. Use base=8<\/code> as a second argument of the int()<\/code> function to specify that the given string is an octal number. The int()<\/code> function will then convert the octal string to an integer with base 10 and return the result.<\/p>\n
Here’s a minimal example:<\/p>\n
>>> int('0o77', base=8)\n63<\/pre>\n
Examples<\/h2>\n
And here’s how you can convert the additional examples shown above: <\/p>\n
>>> int('0o0', base=8)\n0\n>>> int('0o4', base=8)\n4\n>>> int('0o10', base=8)\n8\n>>> int('0o14', base=8)\n12\n>>> int('0o20', base=8)\n16\n>>> int('0o77', base=8)\n63\n>>> int('0o77777', base=8)\n32767<\/pre>\n
You actually don’t need to use the prefix '0o'<\/code> because your second argument already defines unambiguously that the given string is an octal number:<\/p>\n
>>> int('0', base=8)\n0\n>>> int('4', base=8)\n4\n>>> int('10', base=8)\n8\n>>> int('14', base=8)\n12\n>>> int('20', base=8)\n16\n>>> int('77', base=8)\n63\n>>> int('77777', base=8)\n32767<\/pre>\n
However, skipping the base but leaving the prefix raises a ValueError: invalid literal for int() with base 10: '0o77'<\/code>:<\/p>\n
>>> int('0o77')\nTraceback (most recent call last): File \"<pyshell#16>\", line 1, in <module> int('0o77')\nValueError: invalid literal for int() with base 10: '0o77'<\/pre>\n
It assumes that the input string is in base 10 when in fact, it isn’t.<\/p>\n
\"\ud83d\udca1\" Note<\/strong>: Even though passing a prefixed string '0o...'<\/code> into the int()<\/code> function is unambiguous, Python’s int()<\/code> function doesn’t accept it if you don’t also define the base. This may be fixed in future versions<\/a>!<\/p>\n
In fact, you can specify the base argument as 0<\/code> to switch on base guessing—which should be the default behavior anyway! \"\ud83d\udc47\"<\/p>\n
Base Guessing<\/h2>\n
You can pass a prefixed string '0o...'<\/code> into the int()<\/code> function and set the base to 0<\/code> to switch on base guessing<\/em><\/strong> in Python. This uses the prefix to determine the base automatically—without you needing to set it to 16<\/code>. Yet, you still have to set it to 0<\/code> so the benefit is marginal in practice.<\/p>\n
>>> int('0o7', base=8)\n7\n>>> int('0o7', base=0)\n7\n>>> int('0o7', 0)\n7<\/pre>\n
Converting Octal Literals to Int<\/h2>\n
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\"\"<\/figure>\n<\/div>\n
If you don’t have an octal string but a octal number—called a literal<\/strong><\/em>—such as 0xff<\/code>, you don’t even need the int()<\/code> function because Python will automatically convert it to a decimal number<\/a>:<\/p>\n
>>> 0o743\n483\n>>> 0o7\n7\n>>> 0o10\n8<\/pre>\n
Background int()<\/h2>\n
Syntax<\/strong>: int(value [, base]) – > int<\/code><\/pre>\n
\n\n\n\n\n\n
Argument<\/strong><\/td>\nvalue<\/code><\/td>\nA Python object to be converted into an integer number. The value object must have an __int__()<\/code> method that returns the associated integer number\u2014otherwise a TypeError<\/code> will be raised.<\/td>\n<\/tr>\n
<\/td>\nbase<\/code><\/td>\nAn optional integer argument base<\/code> to define the base of the numerical system in the value<\/code> argument. If you set the base, the value<\/code> argument must be a string. The base<\/code> argument determines how the string argument is interpreted.<\/td>\n<\/tr>\n
Return Value<\/strong><\/td>\nint<\/code><\/td>\nReturns an integer number after converting the input argument value<\/code> using its required __int__()<\/code> method for the conversion.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/figure>\n
\"YouTube<\/a>
<\/figcaption><\/figure>\n
Do you still need more background information about Python’s built-in<\/a> int()<\/code> function? No problem, read over the related tutorial.<\/p>\n
\"\ud83c\udf0d\" Related Tutorial:<\/strong> Python’s Built-in int()<\/code> Function<\/a><\/p><\/p>\n","protected":false},"excerpt":{"rendered":"
5\/5 – (1 vote) Problem Formulation Given a string in the octal form: s = ‘0o77′ # or s = ’77’ How to convert the octal string to an integer in Python? For example, you want to convert the octal string ‘o10’ to the decimal integer 8. Here are a few other examples: Octal String […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[857],"tags":[73,468,528],"class_list":["post-130214","post","type-post","status-publish","format-standard","hentry","category-python-tut","tag-programming","tag-python","tag-tutorial"],"_links":{"self":[{"href":"https:\/\/sickgaming.net\/blog\/wp-json\/wp\/v2\/posts\/130214","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sickgaming.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/sickgaming.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/sickgaming.net\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/sickgaming.net\/blog\/wp-json\/wp\/v2\/comments?post=130214"}],"version-history":[{"count":0,"href":"https:\/\/sickgaming.net\/blog\/wp-json\/wp\/v2\/posts\/130214\/revisions"}],"wp:attachment":[{"href":"https:\/\/sickgaming.net\/blog\/wp-json\/wp\/v2\/media?parent=130214"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/sickgaming.net\/blog\/wp-json\/wp\/v2\/categories?post=130214"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/sickgaming.net\/blog\/wp-json\/wp\/v2\/tags?post=130214"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}