Python:Format Printing

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The % operator provides a powerful and succinct mechanism for solving many formatting problems.

The print method

The % operator takes a formatting string followed by one argument or a tuple of arguments. The formatting string includes a number of escape sequences - each of these is substituted by the actual parameter given.
%s  is used when a string is expected
%d  is used when an integer (or long) is expected
%f  is used when a floating point number is expected


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Using % to align

We can format output involving fixed and variable components. Usually we align strings to the left and numbers to the right.


In the % a number of values may follow the % operator. These values are used up by % placeholders in the format string.

The format string is
"Country: %-18s GDP: %20d"
%-18s
the minus in -18 means align left,

the 18 means 18 characters are to be used, the s is for string.

%20d
the 20 means use 20 characters and align right, d is for decimal.
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