prompt: You will be provided with a partial code base and an issue statement explaining a problem to resolve.
  <issue>
  Not all dependecies are listed
  Would it be possible to add pandas (and numpy) to the list of dependencies? They're both imported in various places but not listed. This occasionally causes problems for packages importing plotly, since `pip` may not install all dependencies.
  
  Xref: https://github.com/deeptools/deepTools/issues/669
  Not all dependecies are listed
  Would it be possible to add pandas (and numpy) to the list of dependencies? They're both imported in various places but not listed. This occasionally causes problems for packages importing plotly, since `pip` may not install all dependencies.
  
  Xref: https://github.com/deeptools/deepTools/issues/669
  
  </issue>
  <code>
  [start of plotly/figure_factory/__init__.py]
  1 from __future__ import absolute_import
  2 
  3 # Require that numpy exists for figure_factory
  4 import numpy
  5 
  6 from plotly.figure_factory._2d_density import create_2d_density
  7 from plotly.figure_factory._annotated_heatmap import create_annotated_heatmap
  8 from plotly.figure_factory._bullet import create_bullet
  9 from plotly.figure_factory._candlestick import create_candlestick
  10 from plotly.figure_factory._dendrogram import create_dendrogram
  11 from plotly.figure_factory._distplot import create_distplot
  12 from plotly.figure_factory._facet_grid import create_facet_grid
  13 from plotly.figure_factory._gantt import create_gantt
  14 from plotly.figure_factory._ohlc import create_ohlc
  15 from plotly.figure_factory._quiver import create_quiver
  16 from plotly.figure_factory._scatterplot import create_scatterplotmatrix
  17 from plotly.figure_factory._streamline import create_streamline
  18 from plotly.figure_factory._table import create_table
  19 from plotly.figure_factory._trisurf import create_trisurf
  20 from plotly.figure_factory._violin import create_violin
  21 from plotly.figure_factory._county_choropleth import create_choropleth
  [end of plotly/figure_factory/__init__.py]
  </code>
  
  I need you to solve this issue by generating a single patch file that I can apply directly to this repository using git apply. Please respond with a single patch file in the following format.
  <patch>
  diff --git a/file.py b/file.py
  --- a/file.py
  +++ b/file.py
  @@ -1,27 +1,35 @@
   def euclidean(a, b):
  -    while b:
  -        a, b = b, a % b
  -    return a
  +    if b == 0:
  +        return a
  +    return euclidean(b, a % b)
   
   
   def bresenham(x0, y0, x1, y1):
       points = []
       dx = abs(x1 - x0)
       dy = abs(y1 - y0)
  -    sx = 1 if x0 < x1 else -1
  -    sy = 1 if y0 < y1 else -1
  -    err = dx - dy
  +    x, y = x0, y0
  +    sx = -1 if x0 > x1 else 1
  +    sy = -1 if y0 > y1 else 1
   
  -    while True:
  -        points.append((x0, y0))
  -        if x0 == x1 and y0 == y1:
  -            break
  -        e2 = 2 * err
  -        if e2 > -dy:
  -            err -= dy
  -            x0 += sx
  -        if e2 < dx:
  -            err += dx
  -            y0 += sy
  +    if dx > dy:
  +        err = dx / 2.0
  +        while x != x1:
  +            points.append((x, y))
  +            err -= dy
  +            if err < 0:
  +                y += sy
  +                err += dx
  +            x += sx
  +    else:
  +        err = dy / 2.0
  +        while y != y1:
  +            points.append((x, y))
  +            err -= dx
  +            if err < 0:
  +                x += sx
  +                err += dy
  +            y += sy
  +
  +    points.append((x, y))
       return points
  
  </patch>
golden_diff: diff --git a/plotly/figure_factory/__init__.py b/plotly/figure_factory/__init__.py
  --- a/plotly/figure_factory/__init__.py
  +++ b/plotly/figure_factory/__init__.py
  @@ -1,5 +1,7 @@
   from __future__ import absolute_import
   
  +from plotly import optional_imports
  +
   # Require that numpy exists for figure_factory
   import numpy
   
  @@ -18,4 +20,5 @@
   from plotly.figure_factory._table import create_table
   from plotly.figure_factory._trisurf import create_trisurf
   from plotly.figure_factory._violin import create_violin
  -from plotly.figure_factory._county_choropleth import create_choropleth
  \ No newline at end of file
  +if optional_imports.get_module('pandas') is not None:
  +    from plotly.figure_factory._county_choropleth import create_choropleth
  
verification_info: {"golden_diff": "diff --git a/plotly/figure_factory/__init__.py b/plotly/figure_factory/__init__.py\n--- a/plotly/figure_factory/__init__.py\n+++ b/plotly/figure_factory/__init__.py\n@@ -1,5 +1,7 @@\n from __future__ import absolute_import\n \n+from plotly import optional_imports\n+\n # Require that numpy exists for figure_factory\n import numpy\n \n@@ -18,4 +20,5 @@\n from plotly.figure_factory._table import create_table\n from plotly.figure_factory._trisurf import create_trisurf\n from plotly.figure_factory._violin import create_violin\n-from plotly.figure_factory._county_choropleth import create_choropleth\n\\ No newline at end of file\n+if optional_imports.get_module('pandas') is not None:\n+    from plotly.figure_factory._county_choropleth import create_choropleth\n", "issue": "Not all dependecies are listed\nWould it be possible to add pandas (and numpy) to the list of dependencies? They're both imported in various places but not listed. This occasionally causes problems for packages importing plotly, since `pip` may not install all dependencies.\r\n\r\nXref: https://github.com/deeptools/deepTools/issues/669\nNot all dependecies are listed\nWould it be possible to add pandas (and numpy) to the list of dependencies? They're both imported in various places but not listed. This occasionally causes problems for packages importing plotly, since `pip` may not install all dependencies.\r\n\r\nXref: https://github.com/deeptools/deepTools/issues/669\n", "before_files": [{"content": "from __future__ import absolute_import\n\n# Require that numpy exists for figure_factory\nimport numpy\n\nfrom plotly.figure_factory._2d_density import create_2d_density\nfrom plotly.figure_factory._annotated_heatmap import create_annotated_heatmap\nfrom plotly.figure_factory._bullet import create_bullet\nfrom plotly.figure_factory._candlestick import create_candlestick\nfrom plotly.figure_factory._dendrogram import create_dendrogram\nfrom plotly.figure_factory._distplot import create_distplot\nfrom plotly.figure_factory._facet_grid import create_facet_grid\nfrom plotly.figure_factory._gantt import create_gantt\nfrom plotly.figure_factory._ohlc import create_ohlc\nfrom plotly.figure_factory._quiver import create_quiver\nfrom plotly.figure_factory._scatterplot import create_scatterplotmatrix\nfrom plotly.figure_factory._streamline import create_streamline\nfrom plotly.figure_factory._table import create_table\nfrom plotly.figure_factory._trisurf import create_trisurf\nfrom plotly.figure_factory._violin import create_violin\nfrom plotly.figure_factory._county_choropleth import create_choropleth", "path": "plotly/figure_factory/__init__.py"}]}