C-printf Style
General form |
pf_string1 % ( arg1 [, arg2 ...] ) |
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pf_string2 % { 'name1' : arg1[, ...} ) |
pf_string1 |
" <literal>|<fmt1> ... " |
pf_string2 |
" <literal>|<fmt2> ... " |
<literal> |
any code point outside of fmt is output as is |
%% |
outputs '%' (escape) |
<fmt1> |
% [<conversion-flags>] [<min-field-width>] [<precision>] [<length>] <conversion-type> |
<fmt2> |
% "(" <key> ")" [<conversion-flags>] [<min-field-width>] [<precision>] [<length>] <conversion-type> |
printf-style format specifiers
<key> |
mapping key-anme in passed dictionary |
<conversion-flags> |
"#" |
conversion uses alternative form (see alternative form in format mini-language section) |
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"0" |
0 padded numeric value |
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"-" |
left adjust (overrides zero-padding) |
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" " |
leave space before positive number |
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"+" |
sign character "-" or "+" will preceede the converted number |
<min-field-width> |
"*" |
minimum width read from passed value tuple and must be followed by the value itself |
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<n> |
minimum field width |
<precision> |
"." "*" |
precision read from next value in value tuple followed by th evalue itself |
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"." <n> |
precision, <n> digits after decimal separator |
<length-modifier> |
"h" | "l" | "L" |
ignored in Python |
<conversion-type> |
"d"|"i" |
signed integer |
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"o" |
signed octal |
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"u" |
(obsolte) same as "d" |
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"x" |
signed hexadecimal (lower case) |
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"X" |
signed hexadecimal (upper case) |
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"e" |
floating point number in exponential form (lowercase 'e') |
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"E" |
floating point number in exponential form (uppercase 'E') |
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"f"|"F" |
decimal floating point |
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"g" |
floating point form,at using exponential format iof exponent less than -4 (lowercase 'e') |
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"G" |
floating point form,at using exponential format iof exponent less than -4 (uppercase 'e') |
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"c" |
single character |
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"r" |
string - converts any object using repr() |
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"s" |
string - converts any object using str() |
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"a" |
string - converts any object using ascii() |
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"%" |
literal '%' |
String format
str.format() |
<format-string> "." format( <args> ) |
<format string> |
literal string with <field> definitions |
<args> |
<arg1>, <arg2>, ... |
poisitional arguments referenced by index |
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<kw1> "=" <arg1>; <kw2> "=" <arg2>, ... |
keyword args referenced by name |
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"**" dctVar |
args as dictionary, referenced by name |
<field> |
"{" [<field_name>] ["!" <conversion>] [":" <format_spec>] "}" |
<field_name> |
<arg_name> ("." <attribute_name> | "[" <element_index> "]")* |
<arg_name> |
[<digit>+ | <identifier> ] |
refering by index (positional arguments) or name (passed named arguments or dict variable) (see <args>) |
<attribute_name> |
<identifier> |
<element_index> |
<digit>+ | <index_string> |
<index_string> |
<any-character except "]"> + |
<conversion> |
"r" |
convert to string via repr() |
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"s" |
convert to string via str() |
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"a" |
convert to string via ascii() |
<format-spec> |
see format specification mini-language |
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Formatted String (V3.6+)
"f"|"F" \" <literal>|"{{"|"}}"|<field> ... \" |
<literal> |
literal character |
any code point except "{", "}" or NULL |
"{{" or "}}" |
escape |
outputs "{" respectively "}" |
<field>
<field> |
"{" <fielddef> "}" |
<fielddef> |
<expr> [ "!" <conversion> ] [ ":" <format> ] |
<expr> |
( <conditional_expression> | "" <or_expr>) ("," <conditional_expression> | "," "" <or_expr> )* [","] | <yield_expression> |
virtually any python expressions works here. Some minor restrictions apply. |
<conditional_expr> |
<or_test> [ "if" <or_test> "else" <expression> |
<expression> |
<conditional_expr> | <lambda> |
<lambda> |
python lambda expression |
<or_test> |
boolean expression using "or", "and", "not" and comparisons |
<or_expr> |
bitwise logical and shift expression using "|", "&", "^", "<<" and ">>" |
<conversion> |
"s" |
converted to string via str() |
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"r" |
converted to string via repr() |
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"a" |
converted to string via ascii() |
<format> |
( <literal> | NULL | <field> ) * |
format specifier compatible to str.format() method (see format specification mini-language below) |
Format Specification Mini-Language
<format_spec> |
[[<fill>]<align>] [<sign>][#][0][<width>][<grouping>][.<precision>][<type>] |
<fill> |
<any character> |
fill in the empty space in an aligned value |
<align> |
"<" |
left-aliogn |
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">" |
right-align |
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"=" |
numeric püadding takes place after the sign (like = padding) |
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"^" |
center |
<sign> |
"+" |
show sign for both positive and negative numbers |
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"-" |
show sign for negative nuimbers only (default) |
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<space> |
show space for positive and '-' for negative numbers |
"#" |
alternative form |
(see section below) |
"0" |
"0" in front of the <width> field if no alignment is specified is wual to "0=" fill and align character combination |
number padded by 0 between sign and digits |
<width> |
minimal field width |
<grouping> |
"," |
use comma for 1000 separator (V3.1+) |
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"_" |
use "_" (underscore) for 1000 separator (V3.6+) |
<precision> |
number of digits after the decimal point |
<type> (integer) |
"b" |
binary in base-2 |
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"c" |
character |
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"d" |
decimal integer |
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"o" |
octal integer (base-8) |
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"x" |
hex format (base 16) using lowercase letters |
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"X" |
hex format (base 16) using uppercase letters |
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"n" |
integer number (like "d"), using current locale for number separators |
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None |
same as "d" |
<type> (float) |
"e" |
Exponent (scientific) notation using lowercase "e". Default precision is 6 |
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"E" |
Exponent (scientific) notation using uppercase "E". Default precision is 6 |
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"f" |
fixed-point notation with default precision of 6 |
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"F" |
Same as "f" but "nan" and "inf" are displayed as "NAN" and "INF" |
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"g" |
general format with rounded result at given precision digit |
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"G" |
same as "g" except that uppercase "E", "NAN" and "INF" are displayed |
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"n" |
same as "g" except that it uses current locale for number separator characters |
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"%" |
precentage, multiplies number by 100, displays it in fixed format (like "f") and appends "%" |
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None |
similar to "g" buit has at least 1 digit past the decimal point |
<type> (stzring) |
"s" |
string |
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None |
same as "s" |
Alternative forms (#)
for octal |
"0o" preceeds octal number |
for hexadecimal |
"0x" preceeds hexadecimal number |
floating point |
always contain decimal point even if no digit follows |
if precision is given |
output truncated to precision |
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