Gantt Chart Using Matplotlib

gantt.py

import matplotlib as mpl
from matplotlib import pyplot as plt
from matplotlib.patches import Patch
import numpy as np
import pandas as pd
import seaborn as sns


# Paper 1
paper_1_start = "02/05/2018"
paper_1_experiments_complete = "06/03/2018"
paper_1_analysis_complete = "09/23/2018"
paper_1_submitted = "12/18/2018"
paper_1_revisions_started = "03/25/2019"
paper_1_resubmitted = "05/02/2019"
paper_1_accepted = "06/01/2019"

paper_1_dates = pd.to_datetime(pd.Series([
    paper_1_start,
    paper_1_experiments_complete,
    paper_1_analysis_complete,
    paper_1_submitted,
    paper_1_revisions_started,
    paper_1_resubmitted,
    paper_1_accepted
]))
paper_1_dates.index = [
    "Wet Lab Experiments",
    "Data Analysis",
    "Manuscript Writing",
    "Initial Submission",
    "Revisions",
    "Resubmission",
    "Acceptance"
]

# Paper 2
paper_2_start = "10/15/2018"
paper_2_experiments_complete = "04/19/2019"
paper_2_analysis_complete = "08/01/2019"
paper_2_submitted = "09/29/2019"
paper_2_revisions_started = "11/07/2019"
paper_2_resubmitted = "12/22/2019"
paper_2_accepted = "03/10/2020"

paper_2_dates = pd.to_datetime(pd.Series([
    paper_2_start,
    paper_2_experiments_complete,
    paper_2_analysis_complete,
    paper_2_submitted,
    paper_2_revisions_started,
    paper_2_resubmitted,
    paper_2_accepted
]))
paper_2_dates.index = [
    "Wet Lab Experiments",
    "Data Analysis",
    "Manuscript Writing",
    "Initial Submission",
    "Revisions",
    "Resubmission",
    "Acceptance"
]

# Paper 3
paper_3_start = "01/07/2020"
paper_3_analysis_complete = "04/16/2020"
paper_3_submitted = "05/08/2020"
paper_3_revisions_started = "08/30/2020"
paper_3_resubmission = "10/22/2020"
paper_3_accepted = "3/15/2021"

paper_3_dates = pd.to_datetime(pd.Series([
    paper_3_start,
    paper_3_analysis_complete,
    paper_3_submitted,
    paper_3_revisions_started,
    paper_3_resubmission,
    paper_3_accepted
]))
paper_3_dates.index = [
    "Data Analysis",
    "Manuscript Writing",
    "Initial Submission",
    "Revisions",
    "Resubmission",
    "Acceptance"
]

fig, ax = plt.subplots(1, 1, facecolor="white", dpi=300)
palette = sns.color_palette("Set2", 3)
args = {"edgecolor": "black", "lw": 0.75}

paper_dates_list = [
    paper_1_dates,
    paper_2_dates,
    paper_3_dates,
]
paper_diff_list = [x.diff() for x in paper_dates_list]

paper_labels = []
tick_labels = []
curr_height = 0
paper_zip = zip(paper_dates_list, paper_diff_list, palette)
for j, (dates, diffs, color) in enumerate(paper_zip):
    _start = curr_height
    for i, (name, val) in enumerate(dates.iteritems()):
        if i == dates.shape[0] - 1:
            break
        x = [(val, diffs[i + 1])]
        y = (curr_height, 1)
        rect = ax.broken_barh(x, y, color=color, **args)
        xmin, xmax = ax.get_xlim()
        g = ax.text(
            x=xmin,
            y=curr_height+0.5,
            s=name,
            ha="right",
            va="center",
            fontsize="x-small",
            color=color,
            weight="bold",
        )

        curr_height += 1
        tick_labels.append(g)
    if j == 0:
        offset_1 = 0.1
        offset_2 = 0
    elif j == len(paper_dates_list) - 1:
        offset_2 = 0.1
        offset_1 = 0
    else:
        offset_1 = 0
        offset_2 = 0
    ax.axhspan(
        _start - offset_1,
        curr_height + offset_2,
        color=color,
        zorder=0,
        alpha=0.3
    )

xmin, xmax = ax.get_xlim()
for label in tick_labels:
    label.set_x(xmin - 10)

ax.set_yticks(np.arange(curr_height+1))
ax.set_yticklabels([])
ax.set_ylim([0-0.1, curr_height+0.1])

ax.tick_params("both", labelsize=6)
ax.grid(which="both", alpha=0.5)
ax.set_axisbelow(True)

yr_line_args = {"color": "gray", "lw": 0.7, "zorder": 0}
ax.axvline(x=pd.to_datetime("2018-01-01"), **yr_line_args)
ax.axvline(x=pd.to_datetime("2019-01-01"), **yr_line_args)
ax.axvline(x=pd.to_datetime("2020-01-01"), **yr_line_args)
ax.axvline(x=pd.to_datetime("2021-01-01"), **yr_line_args)


patch_labels = [f"Paper {x+1}" for x in range(3)]
patches = [
    Patch(facecolor=palette[i], label=patch_labels[i], edgecolor="black")
    for i in range(3)
]
ax.legend(
    handles=patches,
    framealpha=0,
    ncol=3,
    loc="lower center",
    bbox_to_anchor=[0.5, 1],
    fontsize="small"
)
ax.yaxis.set_tick_params(width=0)

plt.savefig("gantt.png", bbox_inches="tight", dpi=300)