Fix empty interpolation and add tests for it

pygal/graph/graph.py

@@ -432,8 +432,10 @@ def _points(self, x_pos):
             serie.points = [
                 (x_pos[i], v)
                 for i, v in enumerate(serie.values)]
-            if self.interpolate:
+            if serie.points and self.interpolate:
                 serie.interpolated = self._interpolate(serie.values, x_pos)
+            else:
+                serie.interpolated = []
 
     def _compute_secondary(self):
         # secondary y axis support

pygal/graph/i18n.py

@@ -0,0 +1,190 @@
+COUNTRIES = {
+    'ad': 'Andorra',
+    'ae': 'United Arab Emirates',
+    'af': 'Afghanistan',
+    'al': 'Albania',
+    'am': 'Armenia',
+    'ao': 'Angola',
+    'aq': 'Antarctica',
+    'ar': 'Argentina',
+    'at': 'Austria',
+    'au': 'Australia',
+    'az': 'Azerbaijan',
+    'ba': 'Bosnia and Herzegovina',
+    'bd': 'Bangladesh',
+    'be': 'Belgium',
+    'bf': 'Burkina Faso',
+    'bg': 'Bulgaria',
+    'bh': 'Bahrain',
+    'bi': 'Burundi',
+    'bj': 'Benin',
+    'bn': 'Brunei Darussalam',
+    'bo': 'Bolivia, Plurinational State of',
+    'br': 'Brazil',
+    'bt': 'Bhutan',
+    'bw': 'Botswana',
+    'by': 'Belarus',
+    'bz': 'Belize',
+    'ca': 'Canada',
+    'cd': 'Congo, the Democratic Republic of the',
+    'cf': 'Central African Republic',
+    'cg': 'Congo',
+    'ch': 'Switzerland',
+    'ci': "Cote d'Ivoire",
+    'cl': 'Chile',
+    'cm': 'Cameroon',
+    'cn': 'China',
+    'co': 'Colombia',
+    'cr': 'Costa Rica',
+    'cu': 'Cuba',
+    'cv': 'Cape Verde',
+    'cy': 'Cyprus',
+    'cz': 'Czech Republic',
+    'de': 'Germany',
+    'dj': 'Djibouti',
+    'dk': 'Denmark',
+    'do': 'Dominican Republic',
+    'dz': 'Algeria',
+    'ec': 'Ecuador',
+    'ee': 'Estonia',
+    'eg': 'Egypt',
+    'eh': 'Western Sahara',
+    'er': 'Eritrea',
+    'es': 'Spain',
+    'et': 'Ethiopia',
+    'fi': 'Finland',
+    'fr': 'France',
+    'ga': 'Gabon',
+    'gb': 'United Kingdom',
+    'ge': 'Georgia',
+    'gf': 'French Guiana',
+    'gh': 'Ghana',
+    'gl': 'Greenland',
+    'gm': 'Gambia',
+    'gn': 'Guinea',
+    'gq': 'Equatorial Guinea',
+    'gr': 'Greece',
+    'gt': 'Guatemala',
+    'gu': 'Guam',
+    'gw': 'Guinea-Bissau',
+    'gy': 'Guyana',
+    'hk': 'Hong Kong',
+    'hn': 'Honduras',
+    'hr': 'Croatia',
+    'ht': 'Haiti',
+    'hu': 'Hungary',
+    'id': 'Indonesia',
+    'ie': 'Ireland',
+    'il': 'Israel',
+    'in': 'India',
+    'iq': 'Iraq',
+    'ir': 'Iran, Islamic Republic of',
+    'is': 'Iceland',
+    'it': 'Italy',
+    'jm': 'Jamaica',
+    'jo': 'Jordan',
+    'jp': 'Japan',
+    'ke': 'Kenya',
+    'kg': 'Kyrgyzstan',
+    'kh': 'Cambodia',
+    'kp': "Korea, Democratic People's Republic of",
+    'kr': 'Korea, Republic of',
+    'kw': 'Kuwait',
+    'kz': 'Kazakhstan',
+    'la': "Lao People's Democratic Republic",
+    'lb': 'Lebanon',
+    'li': 'Liechtenstein',
+    'lk': 'Sri Lanka',
+    'lr': 'Liberia',
+    'ls': 'Lesotho',
+    'lt': 'Lithuania',
+    'lu': 'Luxembourg',
+    'lv': 'Latvia',
+    'ly': 'Libyan Arab Jamahiriya',
+    'ma': 'Morocco',
+    'mc': 'Monaco',
+    'md': 'Moldova, Republic of',
+    'me': 'Montenegro',
+    'mg': 'Madagascar',
+    'mk': 'Macedonia, the former Yugoslav Republic of',
+    'ml': 'Mali',
+    'mm': 'Myanmar',
+    'mn': 'Mongolia',
+    'mo': 'Macao',
+    'mr': 'Mauritania',
+    'mt': 'Malta',
+    'mu': 'Mauritius',
+    'mv': 'Maldives',
+    'mw': 'Malawi',
+    'mx': 'Mexico',
+    'my': 'Malaysia',
+    'mz': 'Mozambique',
+    'na': 'Namibia',
+    'ne': 'Niger',
+    'ng': 'Nigeria',
+    'ni': 'Nicaragua',
+    'nl': 'Netherlands',
+    'no': 'Norway',
+    'np': 'Nepal',
+    'nz': 'New Zealand',
+    'om': 'Oman',
+    'pa': 'Panama',
+    'pe': 'Peru',
+    'pg': 'Papua New Guinea',
+    'ph': 'Philippines',
+    'pk': 'Pakistan',
+    'pl': 'Poland',
+    'pr': 'Puerto Rico',
+    'ps': 'Palestine, State of',
+    'pt': 'Portugal',
+    'py': 'Paraguay',
+    're': 'Reunion',
+    'ro': 'Romania',
+    'rs': 'Serbia',
+    'ru': 'Russian Federation',
+    'rw': 'Rwanda',
+    'sa': 'Saudi Arabia',
+    'sc': 'Seychelles',
+    'sd': 'Sudan',
+    'sg': 'Singapore',
+    'sh': 'Saint Helena, Ascension and Tristan da Cunha',
+    'si': 'Slovenia',
+    'sk': 'Slovakia',
+    'sl': 'Sierra Leone',
+    'sm': 'San Marino',
+    'sn': 'Senegal',
+    'so': 'Somalia',
+    'sr': 'Suriname',
+    'st': 'Sao Tome and Principe',
+    'sv': 'El Salvador',
+    'sy': 'Syrian Arab Republic',
+    'sz': 'Swaziland',
+    'td': 'Chad',
+    'tg': 'Togo',
+    'th': 'Thailand',
+    'tj': 'Tajikistan',
+    'tl': 'Timor-Leste',
+    'tm': 'Turkmenistan',
+    'tn': 'Tunisia',
+    'tr': 'Turkey',
+    'tw': 'Taiwan, Province of China',
+    'tz': 'Tanzania, United Republic of',
+    'ua': 'Ukraine',
+    'ug': 'Uganda',
+    'us': 'United States',
+    'uy': 'Uruguay',
+    'uz': 'Uzbekistan',
+    'va': 'Holy See (Vatican City State)',
+    've': 'Venezuela, Bolivarian Republic of',
+    'vn': 'Viet Nam',
+    'ye': 'Yemen',
+    'yt': 'Mayotte',
+    'za': 'South Africa',
+    'zm': 'Zambia',
+    'zw': 'Zimbabwe'
+}
+
+
+def set_countries(countries):
+    global COUNTRIES
+    COUNTRIES = countries

pygal/graph/stackedline.py

@@ -50,5 +50,7 @@ def _points(self, x_pos):
                 serie.points = [
                     (x_pos[i], v)
                     for i, v in enumerate(accumulation)]
-                if self.interpolate:
+                if serie.points and self.interpolate:
                     serie.interpolated = self._interpolate(accumulation, x_pos)
+                else:
+                    serie.interpolated = []

pygal/test/test_config.py

@@ -152,11 +152,20 @@ def test_interpolation(Chart):
     assert len(q(".legend")) == 2
 
 
+def test_no_data_interpolation(Chart):
+    chart = Chart(interpolate='cubic')
+    q = chart.render_pyquery()
+    assert q(".text-overlay text").text() == "No data"
+
+
+def test_no_data_with_empty_serie_interpolation(Chart):
+    chart = Chart(interpolate='cubic')
+    chart.add('Serie', [])
+    q = chart.render_pyquery()
+    assert q(".text-overlay text").text() == "No data"
+
+
 def test_logarithmic_bad_interpolation():
-    try:
-        import scipy
-    except ImportError:
-        return
     line = Line(logarithmic=True, interpolate='cubic')
     line.add('_', [.001, .00000001, 1])
     q = line.render_pyquery()