Download files types python

Return a copy of the string in which each character has been mapped through the given translation table. When indexed by a Unicode ordinal an integer , the table object can do any of the following: return a Unicode ordinal or a string, to map the character to one or more other characters; return None , to delete the character from the return string; or raise a LookupError exception, to map the character to itself.

You can use str. See also the codecs module for a more flexible approach to custom character mappings. Return a copy of the string with all the cased characters 4 converted to uppercase. Note that s. The formatting operations described here exhibit a variety of quirks that lead to a number of common errors such as failing to display tuples and dictionaries correctly.

Using the newer formatted string literals , the str. This is also known as the string formatting or interpolation operator. The effect is similar to using the sprintf in the C language. If format requires a single argument, values may be a single non-tuple object. A conversion specifier contains two or more characters and has the following components, which must occur in this order:. Mapping key optional , consisting of a parenthesised sequence of characters for example, somename.

Minimum field width optional. Precision optional , given as a '. The mapping key selects the value to be formatted from the mapping. The converted value is left adjusted overrides the '0' conversion if both are given. A length modifier h , l , or L may be present, but is ignored as it is not necessary for Python — so e. Obsolete type — it is identical to 'd'. Floating point format. Uses lowercase exponential format if exponent is less than -4 or not less than precision, decimal format otherwise.

Uses uppercase exponential format if exponent is less than -4 or not less than precision, decimal format otherwise. String converts any Python object using repr. String converts any Python object using str. String converts any Python object using ascii. The alternate form causes a leading octal specifier '0o' to be inserted before the first digit. The alternate form causes a leading '0x' or '0X' depending on whether the 'x' or 'X' format was used to be inserted before the first digit.

The alternate form causes the result to always contain a decimal point, even if no digits follow it. The alternate form causes the result to always contain a decimal point, and trailing zeroes are not removed as they would otherwise be. The precision determines the number of significant digits before and after the decimal point and defaults to 6.

If precision is N , the output is truncated to N characters. See PEP The core built-in types for manipulating binary data are bytes and bytearray. They are supported by memoryview which uses the buffer protocol to access the memory of other binary objects without needing to make a copy. The array module supports efficient storage of basic data types like bit integers and IEEE double-precision floating values. Bytes objects are immutable sequences of single bytes.

Since many major binary protocols are based on the ASCII text encoding, bytes objects offer several methods that are only valid when working with ASCII compatible data and are closely related to string objects in a variety of other ways. Firstly, the syntax for bytes literals is largely the same as that for string literals, except that a b prefix is added:.

Single quotes: b'still allows embedded "double" quotes'. Double quotes: b"still allows embedded 'single' quotes". Triple quoted: b'''3 single quotes''' , b"""3 double quotes""". Only ASCII characters are permitted in bytes literals regardless of the declared source code encoding.

Any binary values over must be entered into bytes literals using the appropriate escape sequence. As with string literals, bytes literals may also use a r prefix to disable processing of escape sequences. See String and Bytes literals for more about the various forms of bytes literal, including supported escape sequences. This is done deliberately to emphasise that while many binary formats include ASCII based elements and can be usefully manipulated with some text-oriented algorithms, this is not generally the case for arbitrary binary data blindly applying text processing algorithms to binary data formats that are not ASCII compatible will usually lead to data corruption.

A zero-filled bytes object of a specified length: bytes From an iterable of integers: bytes range Copying existing binary data via the buffer protocol: bytes obj. Also see the bytes built-in. Since 2 hexadecimal digits correspond precisely to a single byte, hexadecimal numbers are a commonly used format for describing binary data.

Accordingly, the bytes type has an additional class method to read data in that format:. This bytes class method returns a bytes object, decoding the given string object. A reverse conversion function exists to transform a bytes object into its hexadecimal representation. If you want to make the hex string easier to read, you can specify a single character separator sep parameter to include in the output.

By default between each byte. Positive values calculate the separator position from the right, negative values from the left. Since bytes objects are sequences of integers akin to a tuple , for a bytes object b , b[0] will be an integer, while b[] will be a bytes object of length 1. This contrasts with text strings, where both indexing and slicing will produce a string of length 1.

The representation of bytes objects uses the literal format b' You can always convert a bytes object into a list of integers using list b. For Python 2. This was a backwards compatibility workaround to account for the fact that Python originally only supported 8-bit text, and Unicode text was a later addition.

In Python 3. There is no dedicated literal syntax for bytearray objects, instead they are always created by calling the constructor:. Creating an empty instance: bytearray. Creating a zero-filled instance with a given length: bytearray From an iterable of integers: bytearray range Copying existing binary data via the buffer protocol: bytearray b'Hi!

As bytearray objects are mutable, they support the mutable sequence operations in addition to the common bytes and bytearray operations described in Bytes and Bytearray Operations. Also see the bytearray built-in.

Accordingly, the bytearray type has an additional class method to read data in that format:. This bytearray class method returns bytearray object, decoding the given string object.

A reverse conversion function exists to transform a bytearray object into its hexadecimal representation. Since bytearray objects are sequences of integers akin to a list , for a bytearray object b , b[0] will be an integer, while b[] will be a bytearray object of length 1.

The representation of bytearray objects uses the bytes literal format bytearray b' You can always convert a bytearray object into a list of integers using list b. Both bytes and bytearray objects support the common sequence operations. They interoperate not just with operands of the same type, but with any bytes-like object.

Due to this flexibility, they can be freely mixed in operations without causing errors. However, the return type of the result may depend on the order of operands. For example, you have to write:.

Some bytes and bytearray operations assume the use of ASCII compatible binary formats, and hence should be avoided when working with arbitrary binary data. These restrictions are covered below. Return the number of non-overlapping occurrences of subsequence sub in the range [ start , end ]. The subsequence to search for may be any bytes-like object or an integer in the range 0 to If the binary data starts with the prefix string, return bytes[len prefix :].

Otherwise, return a copy of the original binary data:. The prefix may be any bytes-like object. The bytearray version of this method does not operate in place - it always produces a new object, even if no changes were made. If the binary data ends with the suffix string and that suffix is not empty, return bytes[:-len suffix ].

The suffix may be any bytes-like object. Return a string decoded from the given bytes. Other possible values are 'ignore' , 'replace' and any other name registered via codecs. By default, the errors argument is not checked for best performances, but only used at the first decoding error. Passing the encoding argument to str allows decoding any bytes-like object directly, without needing to make a temporary bytes or bytearray object.

Return True if the binary data ends with the specified suffix , otherwise return False. The suffix es to search for may be any bytes-like object. Return the lowest index in the data where the subsequence sub is found, such that sub is contained in the slice s[start:end]. Like find , but raise ValueError when the subsequence is not found.

Return a bytes or bytearray object which is the concatenation of the binary data sequences in iterable. A TypeError will be raised if there are any values in iterable that are not bytes-like objects , including str objects.

The separator between elements is the contents of the bytes or bytearray object providing this method. This static method returns a translation table usable for bytes. Split the sequence at the first occurrence of sep , and return a 3-tuple containing the part before the separator, the separator itself or its bytearray copy, and the part after the separator.

If the separator is not found, return a 3-tuple containing a copy of the original sequence, followed by two empty bytes or bytearray objects. The separator to search for may be any bytes-like object.

Return a copy of the sequence with all occurrences of subsequence old replaced by new. The subsequence to search for and its replacement may be any bytes-like object. Return the highest index in the sequence where the subsequence sub is found, such that sub is contained within s[start:end]. Like rfind but raises ValueError when the subsequence sub is not found. Split the sequence at the last occurrence of sep , and return a 3-tuple containing the part before the separator, the separator itself or its bytearray copy, and the part after the separator.

If the separator is not found, return a 3-tuple containing two empty bytes or bytearray objects, followed by a copy of the original sequence. Return True if the binary data starts with the specified prefix , otherwise return False. The prefix es to search for may be any bytes-like object. Return a copy of the bytes or bytearray object where all bytes occurring in the optional argument delete are removed, and the remaining bytes have been mapped through the given translation table, which must be a bytes object of length You can use the bytes.

Set the table argument to None for translations that only delete characters:. The following methods on bytes and bytearray objects have default behaviours that assume the use of ASCII compatible binary formats, but can still be used with arbitrary binary data by passing appropriate arguments. Note that all of the bytearray methods in this section do not operate in place, and instead produce new objects.

Return a copy of the object centered in a sequence of length width. For bytes objects, the original sequence is returned if width is less than or equal to len s. Return a copy of the object left justified in a sequence of length width. Return a copy of the sequence with specified leading bytes removed. The chars argument is a binary sequence specifying the set of byte values to be removed - the name refers to the fact this method is usually used with ASCII characters.

The binary sequence of byte values to remove may be any bytes-like object. See removeprefix for a method that will remove a single prefix string rather than all of a set of characters. Return a copy of the object right justified in a sequence of length width. Split the binary sequence into subsequences of the same type, using sep as the delimiter string.

Return a copy of the sequence with specified trailing bytes removed. See removesuffix for a method that will remove a single suffix string rather than all of a set of characters. If maxsplit is not specified or is -1 , then there is no limit on the number of splits all possible splits are made.

If sep is given, consecutive delimiters are not grouped together and are deemed to delimit empty subsequences for example, b'1,,2'. Splitting an empty sequence with a specified separator returns [b''] or [bytearray b'' ] depending on the type of object being split. The sep argument may be any bytes-like object. If sep is not specified or is None , a different splitting algorithm is applied: runs of consecutive ASCII whitespace are regarded as a single separator, and the result will contain no empty strings at the start or end if the sequence has leading or trailing whitespace.

Consequently, splitting an empty sequence or a sequence consisting solely of ASCII whitespace without a specified separator returns []. Return a copy of the sequence with specified leading and trailing bytes removed. The following methods on bytes and bytearray objects assume the use of ASCII compatible binary formats and should not be applied to arbitrary binary data.

Return a copy of the sequence with each byte interpreted as an ASCII character, and the first byte capitalized and the rest lowercased. Tab positions occur every tabsize bytes default is 8, giving tab positions at columns 0, 8, 16 and so on. To expand the sequence, the current column is set to zero and the sequence is examined byte by byte. Any other byte value is copied unchanged and the current column is incremented by one regardless of how the byte value is represented when printed:.

ASCII decimal digits are those byte values in the sequence b''. See bytes. Return a copy of the sequence with all the uppercase ASCII characters converted to their corresponding lowercase counterpart. This method uses the universal newlines approach to splitting lines. Return a copy of the sequence with all the lowercase ASCII characters converted to their corresponding uppercase counterpart and vice-versa.

Unlike str. Return a titlecased version of the binary sequence where words start with an uppercase ASCII character and the remaining characters are lowercase. Uncased byte values are left unmodified. All other byte values are uncased. Return a copy of the sequence with all the lowercase ASCII characters converted to their corresponding uppercase counterpart.

For bytes objects, the original sequence is returned if width is less than or equal to len seq. If the value being printed may be a tuple or dictionary, wrap it in a tuple. This is also known as the bytes formatting or interpolation operator. Bytes converts any Python object using repr obj. Create a memoryview that references object. Built-in objects that support the buffer protocol include bytes and bytearray.

A memoryview has the notion of an element , which is the atomic memory unit handled by the originating object. For many simple types such as bytes and bytearray , an element is a single byte, but other types such as array.

If view. For higher dimensions, the length is equal to the length of the nested list representation of the view. The itemsize attribute will give you the number of bytes in a single element.

A memoryview supports slicing and indexing to expose its data. One-dimensional slicing will result in a subview:. If format is one of the native format specifiers from the struct module, indexing with an integer or a tuple of integers is also supported and returns a single element with the correct type. One-dimensional memoryviews can be indexed with an integer or a one-integer tuple. Multi-dimensional memoryviews can be indexed with tuples of exactly ndim integers where ndim is the number of dimensions.

Zero-dimensional memoryviews can be indexed with the empty tuple. If the underlying object is writable, the memoryview supports one-dimensional slice assignment. Resizing is not allowed:. For the subset of struct format strings currently supported by tolist , v and w are equal if v. If either format string is not supported by the struct module, then the objects will always compare as unequal even if the format strings and buffer contents are identical :.

Return the data in the buffer as a bytestring. This is equivalent to calling the bytes constructor on the memoryview. For non-contiguous arrays the result is equal to the flattened list representation with all elements converted to bytes. In particular, in-memory Fortran order is preserved. For non-contiguous views, the data is converted to C first. Return a readonly version of the memoryview object.

The original memoryview object is unchanged. Release the underlying buffer exposed by the memoryview object. Many objects take special actions when a view is held on them for example, a bytearray would temporarily forbid resizing ; therefore, calling release is handy to remove these restrictions and free any dangling resources as soon as possible.

After this method has been called, any further operation on the view raises a ValueError except release itself which can be called multiple times :. The context management protocol can be used for a similar effect, using the with statement:.

Cast a memoryview to a new format or shape. The return value is a new memoryview, but the buffer itself is not copied. The destination format is restricted to a single element native format in struct syntax. The byte length of the result must be the same as the original length. This is the amount of space in bytes that the array would use in a contiguous representation.

It is not necessarily equal to len m :. A string containing the format in struct module style for each element in the view.

A memoryview can be created from exporters with arbitrary format strings, but some methods e. A tuple of integers the length of ndim giving the shape of the memory as an N-dimensional array. A tuple of integers the length of ndim giving the size in bytes to access each element for each dimension of the array. A bool indicating whether the memory is C- contiguous.

A bool indicating whether the memory is Fortran contiguous. A bool indicating whether the memory is contiguous. A set object is an unordered collection of distinct hashable objects. Common uses include membership testing, removing duplicates from a sequence, and computing mathematical operations such as intersection, union, difference, and symmetric difference.

For other containers see the built-in dict , list , and tuple classes, and the collections module. Like other collections, sets support x in set , len set , and for x in set. Being an unordered collection, sets do not record element position or order of insertion. Accordingly, sets do not support indexing, slicing, or other sequence-like behavior. There are currently two built-in set types, set and frozenset. The set type is mutable — the contents can be changed using methods like add and remove.

Meanwhile… what part are you stuck on? What do you want to do with it? What have you tried? Add a comment. Active Oldest Votes. The first trick is that this might be a relative URL rather than absolute.

For example: Look for a Content-disposition header with a suggested filename to use in place of the URL's basename. Deal with existing files with the same name. Sorry, I used f as the local file opened by open and r as the result of urlopen because that's what the docs use when they're not using f … but I should have realized that my own code above called it page rather than r. I'll edit it, and thanks for pointing it out. Anyway, yes, binary files are still just files.

Except that on Windows, you may have to be careful to use 'wb' instead of 'w' so Python doesn't try to "fix text newlines" in files that aren't actually text. If you switch to Python 3. Downloading files from different online resources is one of the most important and common programming tasks to perform on the web. The importance of file downloading can be highlighted by the fact that a huge number of successful applications allow users to download files. Here are just a few web application functions that require downloading files:.

These are just a few of the applications that come to mind, but I'm sure you can think of many more. In this article we will take a look at some of the most popular ways you can download files with Python. The urllib. Specifically, the urlretrieve method of this module is what we'll use for actually retrieving the file.

To use this method, you need to pass two arguments to the urlretrieve method: The first argument is the URL of the resource that you want to retrieve, and the second argument is the local file path where you want to store the downloaded file.

In the above code, we first import the urllib. Next we create a variable url that contains the path of the file to be downloaded. Keep in mind that you can pass any filename as the second parameter and that is the location and name that your file will have, assuming you have the correct permissions. Show 4 more comments. Active Oldest Votes. Chris Johnson Chris Johnson The package python-magic-win64 worked for me in Windows — ChesuCR. Add a comment. Richard Richard Both are import magic but have incompatible contents.

See stackoverflow. Richard Do you mind elaborating on the overhead aspect? What makes the python-magic library more efficient then using subprocess approaches? Superb answer.

If you see failed to find libmagic. Check your installation , then run brew install libmagic and try it again — stevec. From the man page : File tests each argument in an attempt to classify it. Community Bot 1 1 1 silver badge. Steven Rumbalski Steven Rumbalski Well, I was hoping someone had a better answer. There's still a lot of work for the OP, it's not a simple function call.

Linux distributions while the python-magic is not and has to be downloaded and installed before it can be used. This is somewhat of a problem if the script using the module is supposed to be portable.

In the case of images, you can use the imghdr module. See doc for optional 2nd param.