python Sao operation --- Print function usage

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python Sao operation --- Print function usage

In Python, print you can print all the variable data, including custom type.

In 3.x is a built-in functions, and has more features.

Parameter options

It can be used help(print) to view print explain the function parameters.

print(...)
    print(value, ..., sep=' ', end='\n', file=sys.stdout, flush=False)
    Prints the values to a stream, or to sys.stdout by default.
    Optional keyword arguments:
    file:  a file-like object (stream); defaults to the current sys.stdout.
    sep:   string inserted between values, default a space.
    end:   string appended after the last value, default a newline.
    flush: whether to forcibly flush the stream.

value: the value of the print can be a plurality of
file: the output stream, default sys.stdout
sep: separators between the plurality of values
end: end, default is a newline \n
flush: whether to force a refresh to the output stream, default NO

1. Type and numeric strings

>>> print(1)
1
>>> print("Hello World")
Hello World

2. Output redirection

By default, print the function will be to print out the contents of the standard output stream (i.e. sys.stdout), can be customized by the file output stream parameters.

with open('data.log', 'w') as fileObj:

　　print( 'hello world!', file=fileObj)

At this time, there will be no standard output, but the corresponding file already has content.

We can also output to the error output stream, for example:

import sys
print('hello world!', file=sys.stderr)

3. separated

>>>print("hello", "world", "hello", "world", "hello", "world", sep="-")
hello-world-hello-world-hello-world

4. Terminator

The default terminator is the line number, end parameters can be modified.

>>>for i in range(10):
           print(">")
>>>>
>
>
>
>
>
>
>
>
>

>>>for i in range(10):
           print(">",end="")
>>>>>>>>>>>>>

5. Wrap

During operation Shi print, print data in the buffer, the buffer is flushed data to the console display

Wherein the cache flush data to the console of the three conditions, one can meet to refresh the display console

1. there is a line break,

2.flush as Ture

3. Run the code or the end of the buffer is full