ValueError: could not convert string to float: 'True'

[wjfwzzc]

version: 0.8.9, Python 3.6.9, reproduction code:

In [1]: from tabulate import tabulate
   ...: data = dict(a=0.1, b=True, c="c")
   ...: table = [(str(k), str(v)) for k, v in data.items()]

In [2]: print(tabulate(table))
-  ----
a  0.1
b  True
c  c
-  ----

In [3]: print(tabulate(table[:2]))
---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-3-16d27c33d4d2> in <module>
----> 1 print(tabulate(table[:2]))

/usr/local/lib/python3.6/dist-packages/tabulate.py in tabulate(tabular_data, headers, tablefmt, floatfmt, numalign, stralign, missingval, showindex, disable_numparse, colalign)
   1299             missing_vals.extend( (len(cols)-len(missing_vals)) * [_DEFAULT_MISSINGVAL] )
   1300     cols = [[_format(v, ct, fl_fmt, miss_v, has_invisible) for v in c]
-> 1301              for c, ct, fl_fmt, miss_v in zip(cols, coltypes, float_formats, missing_vals)]
   1302 
   1303     # align columns

/usr/local/lib/python3.6/dist-packages/tabulate.py in <listcomp>(.0)
   1299             missing_vals.extend( (len(cols)-len(missing_vals)) * [_DEFAULT_MISSINGVAL] )
   1300     cols = [[_format(v, ct, fl_fmt, miss_v, has_invisible) for v in c]
-> 1301              for c, ct, fl_fmt, miss_v in zip(cols, coltypes, float_formats, missing_vals)]
   1302 
   1303     # align columns

/usr/local/lib/python3.6/dist-packages/tabulate.py in <listcomp>(.0)
   1298         if len(missing_vals) < len(cols):
   1299             missing_vals.extend( (len(cols)-len(missing_vals)) * [_DEFAULT_MISSINGVAL] )
-> 1300     cols = [[_format(v, ct, fl_fmt, miss_v, has_invisible) for v in c]
   1301              for c, ct, fl_fmt, miss_v in zip(cols, coltypes, float_formats, missing_vals)]
   1302 

/usr/local/lib/python3.6/dist-packages/tabulate.py in _format(val, valtype, floatfmt, missingval, has_invisible)
    766             return val.replace(raw_val, formatted_val)
    767         else:
--> 768             return format(float(val), floatfmt)
    769     else:
    770         return "{0}".format(val)

ValueError: could not convert string to float: 'True'

If I replace str(v) by v:

In [1]: from tabulate import tabulate
   ...: data = dict(a=0.1, b=True, c="c")
   ...: table = [(str(k), v) for k, v in data.items()]

In [2]: print(tabulate(table))
-  ----
a  0.1
b  True
c  c
-  ----

In [3]: print(tabulate(table[:2]))
-  ---
a  0.1
b  1
-  ---

[astanin]

The basic assumption of tabulate is that values in the same column are of the same type. Though I agree that the exception should not be thrown. The minimal example to reproduce this error is this one:

tabulate([[0.1], ['True']])

[astanin]

Duplicate of #209 ?

[ilya112358]

While looking into this issue I found a similar bug:

>>> tabulate([[1000], ['True']], intfmt=',')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Users\Ibo\Python\python-tabulate\tabulate\__init__.py", line 2176, in tabulate
    cols = [
           ^
  File "C:\Users\Ibo\Python\python-tabulate\tabulate\__init__.py", line 2177, in <listcomp>
    [_format(v, ct, fl_fmt, int_fmt, miss_v, has_invisible) for v in c]
  File "C:\Users\Ibo\Python\python-tabulate\tabulate\__init__.py", line 2177, in <listcomp>
    [_format(v, ct, fl_fmt, int_fmt, miss_v, has_invisible) for v in c]
     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\Ibo\Python\python-tabulate\tabulate\__init__.py", line 1231, in _format
    return format(val, intfmt)
           ^^^^^^^^^^^^^^^^^^^
ValueError: Cannot specify ',' with 's'.

And another one:

>>> tabulate([["1000"]], intfmt=',')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Users\Ibo\Python\python-tabulate\tabulate\__init__.py", line 2176, in tabulate
    cols = [
           ^
  File "C:\Users\Ibo\Python\python-tabulate\tabulate\__init__.py", line 2177, in <listcomp>
    [_format(v, ct, fl_fmt, int_fmt, miss_v, has_invisible) for v in c]
  File "C:\Users\Ibo\Python\python-tabulate\tabulate\__init__.py", line 2177, in <listcomp>
    [_format(v, ct, fl_fmt, int_fmt, miss_v, has_invisible) for v in c]
     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\Ibo\Python\python-tabulate\tabulate\__init__.py", line 1231, in _format
    return format(val, intfmt)
           ^^^^^^^^^^^^^^^^^^^
ValueError: Cannot specify ',' with 's'.

[ilya112358]

All these bugs happen in _format():

python-tabulate/tabulate/__init__.py

Lines 1213 to 1247 in 83fd4fb

	def _format(val, valtype, floatfmt, intfmt, missingval="", has_invisible=True):
	"""Format a value according to its type.
	Unicode is supported:
	>>> hrow = ['\u0431\u0443\u043a\u0432\u0430', '\u0446\u0438\u0444\u0440\u0430'] ; \
	tbl = [['\u0430\u0437', 2], ['\u0431\u0443\u043a\u0438', 4]] ; \
	good_result = '\\u0431\\u0443\\u043a\\u0432\\u0430 \\u0446\\u0438\\u0444\\u0440\\u0430\\n------- -------\\n\\u0430\\u0437 2\\n\\u0431\\u0443\\u043a\\u0438 4' ; \
	tabulate(tbl, headers=hrow) == good_result
	True
	""" # noqa
	if val is None:
	return missingval
	if valtype is str:
	return f"{val}"
	elif valtype is int:
	return format(val, intfmt)
	elif valtype is bytes:
	try:
	return str(val, "ascii")
	except (TypeError, UnicodeDecodeError):
	return str(val)
	elif valtype is float:
	is_a_colored_number = has_invisible and isinstance(val, (str, bytes))
	if is_a_colored_number:
	raw_val = _strip_ansi(val)
	formatted_val = format(float(raw_val), floatfmt)
	return val.replace(raw_val, formatted_val)
	else:
	return format(float(val), floatfmt)
	else:
	return f"{val}"

...when

1. a bool represented as a string is subjected to explicit conversion into a float (L1244),
2. a bool (or an integer) represented as a string is subjected to some integer formatting (L1231).

I'll have a go at fixing those.

Interestingly, this is one of the core functions of the library. It existed as early as in the first commit a83993e of this repo, made more than 10 years ago, although it was much cuter at the time:

python-tabulate/tabulate.py

Lines 26 to 32 in a83993e

	def _format(v, numfmt, isnum):
	"Format value if it is not a string."
	if isinstance(v, basestring) or not isnum or not numfmt:
	return unicode(v)
	else:
	return format(v, numfmt)