4. 自定义色带¶

演示如何创建、修改、删除自定义色带。

添加色带¶

cmap.add() 将自定义色带存入数据库。内置色带不可覆盖。

In [1]:

from multicolor import cmap

cmap.add(
    name="SunsetGlow",
    colors=["#2d004e", "#8b2fc9", "#d4a0ff", "#f9a825", "#ff5722"],
    cmap_type="diverging",
    tags=["custom", "warm"],
    colorblind_safe="none",
    description="Purple-to-orange diverging colormap for custom use.",
    source=["user"],
)

custom = cmap.get("SunsetGlow")
cmap.preview(custom, title="SunsetGlow")

from multicolor import cmap cmap.add( name="SunsetGlow", colors=["#2d004e", "#8b2fc9", "#d4a0ff", "#f9a825", "#ff5722"], cmap_type="diverging", tags=["custom", "warm"], colorblind_safe="none", description="Purple-to-orange diverging colormap for custom use.", source=["user"], ) custom = cmap.get("SunsetGlow") cmap.preview(custom, title="SunsetGlow")

输入验证¶

cmap.add() 会验证输入，防止无效数据进入数据库。

In [2]:

# 无效 hex 颜色
try:
    cmap.add(name="Bad", colors=["not-a-color"], cmap_type="sequential")
except ValueError as e:
    print(f"Rejected: {e}")

# 无效的 cmap_type
try:
    cmap.add(name="Bad", colors=["#ff0000"], cmap_type="gradient")
except ValueError as e:
    print(f"Rejected: {e}")

# 空名称
try:
    cmap.add(name="", colors=["#ff0000"], cmap_type="sequential")
except ValueError as e:
    print(f"Rejected: {e}")

# 无效 hex 颜色 try: cmap.add(name="Bad", colors=["not-a-color"], cmap_type="sequential") except ValueError as e: print(f"Rejected: {e}") # 无效的 cmap_type try: cmap.add(name="Bad", colors=["#ff0000"], cmap_type="gradient") except ValueError as e: print(f"Rejected: {e}") # 空名称 try: cmap.add(name="", colors=["#ff0000"], cmap_type="sequential") except ValueError as e: print(f"Rejected: {e}")

Rejected: Invalid hex color: 'not-a-color'. Expected format: '#RRGGBB', e.g. '#ff0000'.
Rejected: Invalid cmap_type: 'gradient'. Must be one of {'diverging', 'sequential', 'qualitative'}.
Rejected: Colormap name must be a non-empty string.

覆盖自定义色带¶

In [3]:

cmap.add(
    name="SunsetGlow",
    colors=["#004e1a", "#2fc98b", "#d4f0ff", "#a825f9", "#2257ff"],
    cmap_type="sequential",
    tags=["custom", "updated"],
    description="Updated version.",
)
cmap.preview(cmap.get("SunsetGlow"), title="SunsetGlow (updated)")

cmap.add( name="SunsetGlow", colors=["#004e1a", "#2fc98b", "#d4f0ff", "#a825f9", "#2257ff"], cmap_type="sequential", tags=["custom", "updated"], description="Updated version.", ) cmap.preview(cmap.get("SunsetGlow"), title="SunsetGlow (updated)")

内置色带受保护¶

In [4]:

try:
    cmap.add(name="Viridis", colors=["#000000", "#ffffff"], cmap_type="sequential")
except ValueError as e:
    print(f"Blocked: {e}")

try:
    cmap.remove("Viridis")
except ValueError as e:
    print(f"Blocked: {e}")

try: cmap.add(name="Viridis", colors=["#000000", "#ffffff"], cmap_type="sequential") except ValueError as e: print(f"Blocked: {e}") try: cmap.remove("Viridis") except ValueError as e: print(f"Blocked: {e}")

Blocked: Cannot overwrite built-in colormap 'Viridis'. Use a different name.
Blocked: Cannot delete built-in colormap 'Viridis'.

删除自定义色带¶

In [5]:

# 先确认存在
print("Before:", "SunsetGlow" in cmap.names())

# 删除
cmap.remove("SunsetGlow")

# 确认已删除
print("After:", "SunsetGlow" in cmap.names())

# 先确认存在 print("Before:", "SunsetGlow" in cmap.names()) # 删除 cmap.remove("SunsetGlow") # 确认已删除 print("After:", "SunsetGlow" in cmap.names())

Before: True
After: False